Thank you for helping me work through it. I think i got it. Starting with Wikipedia, the Title VIN and number plate under the front windshield. If your stamped in vin numbers on the right front top fender well and your rear trunk floor just behind your right rear tail light housing are matching your driver door sticker VIN your golden. Now you just need to make sure your engine numbers match the year specified on samba's engine code list. Then your transmission numbers need to match to the year specified by the list provided by Blue sky motorsports chart for the year of the vehicles vin. All of this can be fabricated into any car by a good HACK ! This would qualify as ( Matching Numbers ) I think so ? Thoughts please.

In it's simplist form 'matching numbers' means the car has the engine and transmission
that it was manufactured with.
The stamped in VIN numbers are the starting point.
There are 'stamped' numbers on the engine the transmission and even dates of manufacture on many components such as alternator, starter, wheels and others.
It is determined by history and evidence that can be found in a few ways.
The original window sticker is a basic record, factory records such as a COA,
(certificate of authenticity) maintenance records and a few other means help to
determine matching numbers.

Thank you, this helped. I have never seen a COA but I worked through some of this equation and i got it. Wikipedia has a set of numbers to match to the Vin. Samba has a set of Letters to match for the engine cases. Blue sky motorsports has a chart to match transmission numbers. As long as you get the right set of numbers on the components you put into the vehicle assuming you know where the stamped vin numbers are located it all can be put together minus the door sticker and even that can be welded in, would you agree ?

For Porsches, number matching includes:

Chassis number
Transmission number
Engine number
VIN number

They all work together. The factory kept records of these items and wrote them down. The COA (there is a newer product/term for that now from Porsche) links all those together, along with Exterior and Interior color, wheel style, options on the car (radio, Alloy wheels, "US Equipment" etc).

The VIN stamp is in several places too.. So if a car has had its front clip replaced due to an accident, you can likely see two vins or a poor job of someone hacking up the plates.

So.. when you have the underlying build document and you compare it to the car, you can know how "factory original" the vehicle is.

A COA will note if the VIN matches the engine number number it left the factory with. It will not tell you what the matching engine number was if it doesn't match. I think I saw one person who had a transmission match noted on their COA (could be wrong about that), but normally is noted as "Not Confirmed" at least for 914/4s. When I inquired about that on mine, I was told that PCNA doesn't have records for transmission numbers. My COA does not list the chassis number although both VIN and chassis number are stamped into the chassis of the car.

The information the COA gives about optional equipment is notoriously bad. Mine simply states USA base equipment even though it has the sport package with Fuchs, center console, and factory sway bars. They at least got the interior color correct.

The older COA actually provided the factory numbers... Later COA's would ask you for your numbers and confirm if yours was correct or not. It was an odd process change by Porsche.

Now you can have two different types.. with fancy new names... one is just the COA with a new name.. The other has you take you car to a dealer to be "authenticated" and costs like $600.

I have 2 COA's for my 914/6. One from 1990 or so an another from 2016?. There are slight differences between the two but both have the same engine/chassis/vin info.

Rusty somehow ended up with 3 COAs for Elwood that he passed along to us. All of them had different listings for the optional equipment, so I always take the info from a COA with a large grain of salt.

Clay

And somewhere in there is some of the real story.. When its all you have, or all that is available, its what you use.

If these cars were still only 15 years old and seemingly worth nothing, no one would really care. Add time, scarcity and a lost knowledge gap and now even the less right things hold more water than nothing at all.

When a COA was compiled they ran into issues with the interpretation of options from the numbers listed on file. They erroneously use numbers from 911s and not 914s.
I have not heard of errors in the engine numbers or exterior colours...please correct me if I am wrong.

David Pateman has compiled a very accurate option number list and he can still get the COA information for 914s.

Glenn,
I would not be surprised that Porsche would use the 911 numbers instead of the 914 numbers.

Clay

My COA is practically worthless. Even only has a Misc paint code of M21 as they don’t recognize the VW paint codes, in my case L64K for 1974 Zambezi Green. Even sent them photo of trans number as its original but they wouldn’t/couldn’t verify on COA.

I ordered the COA for my -6 about 5 years ago. When I sent in the application, I included every number I could find on the car. It came back with both the engine and transmission numbers listed. It did not include the chassis number as I discovered I missed a digit on my note.
Color code (15) is correct even though it is not listed on the door jamb plate.
options show as US equipment, leather steering wheel (didn't they all have it?), and Dunlop 165-15 tires (replaced with 185/70-15 before I bought it).

I'm sure we could get a lively discussion going with 'original' vs 'matching'. If my engine blew and wasn't repairable, but I replaced it with an identical one from the same model year, it's no longer 'matching' but technically original equipment.

I'd love to see that CoA.
The paint codes they use are the sales codes, and that is common for most CoA's, not just 914's.
They cannot confirm the transmission # if it is not in their records, and it seems that all 914 transmission #'s were not recorded, and many of the 911 ones also.
One can only obtain what there is to be had.

I don't think the production # or Karmann # are ever listed on a CoA. And they are different #'s even if they are identical on a car. Most early 914/6 numbers are not matching, and on most 914/4 they do match in my experience. The number the Factory has in it's records is the production #, the handwritten # up under the dash that few have ever seen.
The CoA department has no idea about paint codes, they place the number they have on the CoA, not knowing what number is actually on the plate. They have no idea about dates either. Most dates that are in the Factory record are Invoice dates; not particularly useful, but they don't know that. My Reports correct most of that information.

In doing my research on the test mule I have several emails conversations with Jurgen Barth. Here is a quote from one of them:

My remaks came out of the Production book but i do not think we will find other detailed info about this car because at this time the Financial Controlers made us destroi all Files after 5 Years because it uses space and that the reason to day no other info awailible
Best regards
Jürgen

I would gather from that statement that 914 records are lost for good. I also happen to know that there is nothing of any substance in the factory archives regarding 914's.

My guess is that Jurgen has access to old records that he alone has stashed somewhere.