Did you make those from a 'block', or start with an existing set and trim them down and reshape them to this style?
There appears to be old checkering not quite removed from the surface behind the outlined area and some in front of it as well out onto the finger grooved area (especially seen on the RH grip).
If you checkered them first, I would have stayed with that and not gone to the wood burning effect.
Either checkered or a plain smooth surface and then a nice wood finish .
Staining the wood you mentioned they needed yet and I agree on that.
Different medallions, use matching S&W if it's for a S&W. and make sure they fit nice and tight in their counter bored holes.
Take time to rotate them in position for best effect when viewing.
The RH (penney) medallion doesn't fit all that well.
Any medallions used need to fit tightly in their recesses.
The LH 'medallion' looks like a commercial made impression stamped right into the wood.
Keep at it,,we all start somewhere!