Assuming it IS a numbers matching car, & you're going to bare metal for a repaint, then the best value would be to return it to the original factory color - whether or not you do rust repair. For a modified car or with replacement engines, etc. - the following won't apply, or not as much so.
Despite any opinions either way on here - the real world classic/vintage/sports/exotics car market valuation factors are pretty clear, so read from the experts at Hagerty's website & in their & Hemmings' publications' articles on the value differences on restorations original vs. color changes, & that holds for really any classic/collectable car/vehicle across the board (maybe 914s are so scarce in Sweden that they won't care).
That said - it's your car & your project & your dough, so in the end you have to be happy, & the ultimate value loss may not be significant to you personally. If you can find one of the factory 914 or 911 colors which work for you, then I think that the value difference will be less.
You can see actual 914s in the various factory colors for every MY at the link below by clicking on each color silhouette ....
p914.com (you may have to manually change to .org or .net if some link still aren't fixed)
Now this is coming from a serial color changer on my `73 914 2L since I bought it in 1975 (oh, the impetuousness of youth!
) - I did the 914 Copper in `76 with a rustoration repaint, then the current Anthracite Grey in my 1980 rolling resto/rusto (see avatar pic) - & that was on top of what turned out to be 2 other color changes by the dealer &/or prior original owner from L80E Light Ivory (white) originally, to Sahara Beige then Gold (both 914/911 colors.
Moreover, it was common for P+A dealers back then to do color changes for buyers - especially when they were moving hot & special orders were backed up or long waits, & for the opposite to move a slow selling car (mine was built 8/31/72 & first registered 11/6/72 - so probably the former).
However, after my 2 prior restos/color changes & 2 prior repaints - in my current resto I'm going to take it back to the original L80E on my bare metal resto since mine is numbers matching, I have all records since 1975 (2nd owner), & it's going to bare metal - essentially erasing the sins of the past. So I put myself on a white 914 desensitization program to get myself used to it in the original color - the dealer sold "PORSCHE" positive side stripes will help, & think that I've gotten over my "white cars look like refrigerators" mania!
Believe me - I would MUCH prefer, as would my wife, to repaint in either Alaska Blue or Marathon Blue metallics - always my FAV 914 factory colors from `73 MY
- but the reality is that:
1.) I'm putting a ton of dough into getting my "ole gal" fixed/rusto'd/restored, &
2.) In my mid-60's, I have to face reality that at some point my wife &/or kids will need to sell it, & will probably need to get top dollar out of it when I'm gone.
It ultimately comes to your choice as to whether you'd prefer to have your fav color, or to have a few $1000s or $10,000s in value if/when you sell - it's each persons' choice.
Who knows, I may get a last minute "wild hair" & push from my wife, to make mine blue anyway!?
I've heard that some just flip a coin!
Good Luck!
Tom
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