Roy, I've always taken it that those very few rifles that for whatever reason did not get sent back to the UKto be stripped for usable spares at Weedon now form the sole reservoir of original rifles. My original PPCo rifle was one of a batch of several thousand SMLE's that had been stored in a warehouse in Egypt for decades, until Ryton Arms bought 1200 of them in the early 1990's. Out of that 1200 there were two rifles that still bore bases (scopes long gone, of course). One of them was a BSA rifle & it was bought by Tony Hallam for his son Robert's collection (the Charnwood collection that was auctioned at Bonhams in 1998). Paul Varley, the then manager of Ryton, kept the slightly better of the two for himself (an EFD 1916). In about 1996 I managed to do a deal with him as he needed a couple of No32 scopes really badly - so we did a swap. Both of us were happy, & I still have the rifle.
In practice we are often assisted in distinguishing the right from the wrong, simply because most of the fakers are so bad at it............their desires outweigh their abilities, at least in most cases. Long may it stay that way!