I have 2 mid-grade box locks that came with wood extensions and checkered butts. The extensions are well done, and the color is close, but the grain does not really match.
I initially thought that I would have them restocked or butt grafted. But after hunting them, I find that I really do not see those extensions anymore.... I enjoy looking at the actions, at the engraving, and at the checkering, but the extensions just do not bother me. A pleasant surprise, actually.
Quality restocking would probably cost more than I paid for those guns. So I am enjoying them the way that they are.