I was involved in at least one of the recent conversations about replacing the small Siler flint with a more appropriate English type on a pre-inlet stock. Dennis Glazener suggested looking at a Late Ketland from Chambers, and it turned out to be a pretty close fit as far as covering up the original mortice. I'm done with the re-inlet on my stock and ended up gluing in some more maple at the lower tail of the lock as filler at the side of the plate, and also gluing in some maple strips to move the lock plate out about 1/16" to keep it's face parallel with the plane of the lock panel after the bolster made contact with the barrel. I did that instead of filing the bolster because I was worried about clearance in the mortice for the Ketland's wider mainspring. I still have a very slight gap between the plate and the inlet on about 1/2 of the arc of the bottom of the plate- between it and the bottom of the original inlet. After I get closer to the final stock sanding and finish, I'll decide what -if anything- to do about that....
If that was a good and proper solution to the problem, I don't know.... but it seemed like a good idea at the time!! I'm really shooting for when someone knowledgeable sees it, they'll just think " Hmmm that lock has been replaced" instead of "What in the #$** happened to that thing???"
(Oh yeah- my stock is a fairly recent one from the Log Cabin Shop.)