On a sxs shotgun? It's to fill a gap around the front finial of the trigger plate. Should it be just thick enough to go to bottom of the trigger plate inletting, or deeper? Trigger plate is about 1/8" thick, and there is plenty of wood under the plate to make the inlay 1/4" thick. I have a piece of ebony left over from a knife project big enough to fill the gap. Thought is to make it just a large oval, about .75 wide x 1.5" long, around 'pineapple' potion of the trigger plate.
I think I'd rather have a contrasting inlay than trying to match up this walnut, but I've also heard there are issues with gluing ebony to other woods. I also have some mahogany that might not stand out after finishing, that might be easier to glue in.
This is on a Pedersoli kit that an acquaintance was never going to finish. I'm putting a screw into the standing breech, but it ends up in exactly the thinnest part of the trigger plate, with not enough material to support a screw. Plan is to cut the plate, weld material in to make it longer, but this will put the 'pineapple' finial (ha!) at least 1/4-3/8" ahead of the factory inletting.