I beleive that the FAA is indeed working at an new a/c class description for Vintage machines that will allow the use of parts not necessarily designed for that a/c. What we in Canada affectionally call the "Owner Maintenance Class" which the FAA stubbornly will not recognize and allow flying in the US sky... oh well.
This to allow old planes to continue flying, even so some parts cannot be procured anymore. Kind of like the Experimental category mixed with homebuilt. Best example of this situation is old style gas selector valve in the C-140. Original was just like one from a John Deere tractor ! Not available anymore, while there are perfectly good and better new ones on the market. Not STD'd or PMA'd, can't use them on your certified bird !
I cannot begin to imagine how one keeps finding some parts for many of the warbirds still flying today... Specially when there are so little of them left flying !
