[weemark]

a lot of NOS parts are still on the shelf for a reason - a lot of them are 2nds at best and they just aren't right hence the reason they have never been used and still sitting on a shelf but someone doesn't want to get rid of them for whatever reason but then these parts end up on the market as NOS and the rest is history...

You seem to be getting hung up on little details and making what should be a simple build incredibly complicated. As someone up thread said find an old timer who has built lots of these engines to work with and get them to build yours.