guesser's advice is good. Neither of the bullets you have are very good choices for a .32-20 revolver.

Speer's Number 13 manual, the newest I have, lists data for a cast 98 grain SWC bullet. With this bullet they list charges (start/max) of 3.0/3.5 of Unique and 2.4/2.9 grains of Bullseye. These are both under the industry pressure limit of 16,000 c.u.p. and keep velocities under 1,000 for cowboy action shooting limits.

Yes, the brass is thin but so are other old cartridge case designs. Use a good lube (I like Imperial sizing wax, I think now made by Hornaday), take your time in making sure the cases are all the way into the shell holder before working the press handle and you won't have any problems.

I, too, shoot the cast Lyman 3118, although it has been a while since I made any. I usually loaded it over Unique. It shot close to point-of-aim in my 4 inch .32-20 M&P, a short Colt Bisley and a very old Marlin 1894 lever action. With your older revolver, go with the milder ranges of data you find. Do not use data for rifles or for Thompson/Center Contenders.