I did expoxy pins to hold cape buff horn down..cause I didnt think it would stay without them.
I did as you said- drilled through liner and then through a little bit of the scale from teh inside, and through the tang as well, to run a "rod" of epoxy all the way through to both scales.
Took a lot of work...was kind of scary because I wasnt sure I could get the finish on teh scales I wanted without running it down to the pins..but it all worked out.
I have heard of hidden real pins on things like bolsters...but havent tried those.