How long is a piece of string?

The point of an owner produced part is that it needs 50% or more of the input to be from the aircraft owner, and that can be in management, design, fabrication. You don't have to make the whole thing.

It might be as simple as fabrication aluminum baffles for an engine. It might be for a support bracket for supporting a battery. There are a lot of times where an owner produced part can be made quickly, cheaply and can be signed off by an A and P mechanic.

@patricbarry Thank you.  I had never really heard of this until this forum and, with the aging fleet, will probably be an issue going forward.  Do you know if there is a clearinghouse on the site for successful parts creation?

A clearinghouse for parts?  

A clearinghouse for parts is risky since the quality is often risky. An IA (A&P with Inspection Authorization) has a responsibility to yellow, red or green tag a part for reuse, but private folk don't do that, so used parts might not pass muster. When we buy from parts yards the dismantler will inspect a part before shipment.  There is always Trade A Plane and Barnstormers, both which carry ads for parts, and Webco is a great source. Matt Kurke at www.comanchegear.com stores parts for resale and he makes nifty wiring harnesses for the underwing landing gear. Matt also services landing gear motors and transmissions - he is an excellent contact. 

 An IA removes a suspect part and the FAA requires that we destroy it so it doesn't get mixed up with good quality parts, but private owners may be unfamiliar with that requirement which is why some purchases off EBay, for example, might be poor quality.

In practical terms, there are avenues to buy new and recycled parts and with resources like Matt Kurke and Webco who do repairs of components the fleet is generally well supported.

I send boost pumps to Marci at Aviation Ideas in Washington State and they attach a new motor - it's really a whole new pump although by using the shell it is a repair, so this is a resource for you to remember. 

Thank you, very informative.  I wasn't clear, my question is there a list/clearinghouse of parts owners have produced.  I don't even mean a lot of detail (but that would be great, of course), just what has been produced so I would know what has been done - so if I need the part I can move with more confidence to produce.