Looking for a vendor of these…

I have some but never use them. I use 12mm wave washers like were used on nearly all other Porsche calipers

If you just need 2, send me a PM...I have a bunch

This is one of the few instances where I'm going to argue that original engineers put parts on these vehicles that are not needed.

Agree completely with @Bdstone914 . These are not needed. If you feel they are, you can reuse what you have, make your own version, or safety wire the fasteners.

A properly torqued bolt doesn't need a locking tab. You will not find these on modern brake hardware. Properly torqued alludes to the use of a toruqe wrench and not just a "well that is tight enough" approach to tightening fasteners.

Over time, the science of bolted joint design has progressed since the 70's and it has been proven that adding additional components into a bolted joint like this soft sheetmetal plate, and/or split ring lock washers DEGRADES the robustness of the bolted joint.

I would post more about why a Failure Mode Effects Analysis would indicate that a single fastener loosening would not be catastrophic failure but suspect no one really cares about the details. We'll leave that for another time.

I would supsect that the reason they are NLA is due to the fact that they are not needed. Similarly, the lack of support by the aftermarket suggests that people weren't willing to pay for them to be replaced at each use.

Agreed. A lot of folks don't understand how bolts are supposed to work. A bolt should never be subject to shear loads...the bolt should only be subject to tension, do to tightening. A properly tightened bolt creates a joint between 2 things with adequate clamp force between the two things to support all the loads that the joint will be subjected to. If ever there is a situation where that bolt is subject to a shear load, that means the joint has failed or the fastener was inadequate to create the necessary clamp for that joint.

I've never had a properly tightened fastener loosen up. Sometimes I'll add some threadlocker for the hell of it, but mostly for liability reasons (belt and suspenders never hurts)...but then the torque value must change to accomodate for the lubrication properties of wet thread threadlocker.

Keep in mind a torque value is a round-a-bout manner to arrive close to a specified level of fastener tension. It is only used because it's the easiest way to get pretty close in the field. Torque value specifications only guarantee the correct fastener tension if using a new fastener, perfect new condition threads, and clean and flat mating surfaces. Its rare that these conditions exist on a 50 year old vehicle, so a bit of insurance is not a bad thing, but rarely necessary.

Good points made above; appreciate the input. I'm using the parts make an offset spacer for my rear calipers. The car has. vented rotors and PMB V calipers. In the past, I've struggled getting washers and rock protectors into position. The front caliper locking washers will be used in place of the round washers.

Do these bolts have a history of backing out?

safety wire may be an option

There is no history of them coming loose if properly torqued.

If you anyone wants evidence of how those locking tab plates soften the joint, look at the deformation that has occurred on the sheetmetal under where the washers were. That is by definition a soft(er) joint. The cast iron of the caliper, the strut spindle, and the bolt head are all harder than that piece of soft sheetmetal was therefore it basically extruded under the clamp load and clamping force was lost when it deformed.

There are no production vehicles runing around with safety wire . . . that is a sign that it is of no consequence except in the limited scope of racing and the craziness that happens in the paddock. Millions of miles on road going vehicles bears this out.

In the case of racing, I appreciate why safety wire is there.

Thanks Phil, it's great having an engineer "on staff"