Thanks, all. Little Joe- Greg Roberts at the GRRW when he inspected the rifle in November, 1975 and traced the outline and took measurements and made notes, said "cast iron nosecap". The one I used is a cast steel 1 1/8" from Muzzleloader Builders Supply, order number 29400, a match. Doc White said the nose cap had been silver plated, which wore off, OR was case hardened. The butt plate, lock and plug and tang were, too, also the trigger guard.
Oldarcher, I'll post the rest of the photos here. If you need a direct copy, I can E-mail to you. I have my photos on Photobucket but don't know how to do a photo address.
Don- Greg Roberts' notes said 11 1/4 pounds. My barrel was 2.25" shorter and so my rifle weighs 10 pounds 12 ounces. Though heavy, with that short 13.25" LOP, I can shoot it offhand, some.
The commercial parts I used to build my rifle were the correct ones, with slight differences in lock length and trigger spacing as noted. The butt plate return was not long enough, but the BP was a match, with the inside corner filed square. The 3.8" toe plate is not matched by Track's 4 1/8" long #TP-TC-H-I, but I did not have a picture of it from GRRW. My photo above shows it. It is riveted to the butt plate, and Carl Walker told me they took the two off together. If anyone wants it, I can list the parts and stains I used. I can also post the 60 some dimensions I have for the original rifle. Just a matter of knowing how to get it posted on here.