My unadorned 1860 as modified to shoot the Cowboy45Special"  , and there's room for 8 more rounds in the magazine! 

You will see where 3f 777 is not recommended for cartridges This is because a full case of 3f  in the 45 Colt will exceed SAMMI spec for that cartridge. Then again so will a case of 3f OE or Swiss.  I like using such powders in cases like the 38s, 44 Russian, 45 CS etc.

  Iron Badger 

Oopsies.  I neglected your original question.  I honestly don't know.  Whenever I worked on '92s I simply worked on the OEM parts.  I never tried swapping between manufacturers.  I will say, to most outward appearances, everybody copies the original '92 fairly closely.  It doesn't take much for something to NOT FIT however.

Steve at Stevesgunz would be a much better source.  If he doesn't know, nobody does.

I suppose you can add me to the list.  About 2008 I dropped in at EMF and was just visiting with Grn'l Grant, when he up and offered me one of theh last rifles he received from Uberti in 45 Colt as I had one of the 1st five 45 Colt rifles imported into the US thu him. So I became the proud owner of a Steel Framed 1860.  I'm now waiting on a Carbine length Steel Frame 1860.

  Iron Badger 

There is a much more elegant and cheaper solution.  Contact Nate Kiowa Jones (Steve Young) at Stevesgunz.  He offers a nifty little kit that eliminates that stupid safety.  The only remnant of the safety is Steve's little "button" plug which disappears at 6 feet.

While you're at it, buy Steve's DVD for tuning up the Rossi and his Spring Kit.  You won't believe the difference it will make in the gun.

No, I don't receive promotional considerations, remunerations, or even acknowledgement from Stevesgungz.  Steve is just a fellow gunsmith whom I recommend.