Dear Guys,
Thanks for the replies. Stupid me, for some reason I thought that there were federal regulations which defined how to de-mill any modern firearm. But, the only thing I have found is the reference to cutting the receiver into pieces.
Yes, I realize that if I spot weld a steel plug into each barrel, then they would be almost impossible to remove, and the piece could not be resurrected. But, that is my specific goal.
This piece doesn't have percussion nipples, but instead has external firing pin links, struck by external hammers. So, I would probably disable those links as well.
In my opinion, at some point in its late life, a totally worn out wallhanger piece should be totally disabled, to prevent some curious little twerp pre-teen boy from taking it down from the mantle and dropping a modern shell in it 30 years from now to see if it will go bang in the back yard. (He may even be my great great grandson!)
Best Regards,
Mannyrock