If you are talking about American longrifles; with the exception of the thumb-piece on the wrist, you really don't see much in the way of silver inlays until the mid-1780's. There are exceptions of course like C. Oerter, but in general the 1790's seems to be the beginning of the popularization of numerous silver inlays on American longrifles. Further complicating this interpretation is addition of inlays on an early rifle at a later date, such as a silver star added on the cheek piece. Many years ago I owned a rifle that was probably from the around 1780 that had a star added in the 1810 range based on the Federal style of the star and engraving, possibly an attempt at modernizing it? So in my opinion, if you are stocking a rifle, a reasonable date to look at is mid-late 1780's 1790 as rule to guide you on the style of rifle one would feel justified in adding silver inlays.
Bruce
