Dixie Gun Works supposedly has a couple of the screws for originals.  Another option would be to find a machinist to make them for you.  Might be worth asking places such as S & S Firearms if they have what you need.  Sometimes parts places have a few parts they don't have enough of, or enough demand for, to advertise.

Or someone who knows enough to be able to find screws with the correct threads that can be re-purposed for your current project.  S&S was able to help me put together a Portugese cigar-box gun (all the action parts were loose in a cigar-box, and all the screws were missing) despite having no parts that were actually from or for the Portugese gun. 

Well, for whomever might be interested, DrummerBoy hisself here with some new acquisitions toward the “All Four” goal. I now have brass in all four calibers. As a neophyte I just do what comes easiest for the time being.  45-60 and 50-95 in cowboy loads from Steinel, 40-60 from Graf (Jamison) and now 45-75 that Mr Palazzo at Ammunition Artifacts makes from Starline 50 Alaskan. Obviously I’ve shot the rounds from Steinel so they work … all I can do at this time is drop the 40-60 and the 45-75 into their respective barrels which I did and both drop right in…more rigorous testing to come
I did manage to get the three-die legacy sets for the 45-60 and the 50-90..I know that it’s possible to get the Lyman 310 in every caliber except the 50, but who knows when that’ll turn up…lastly I’m gonna try to slug all  the bores with some of these 54 caliber Hornady balls…..”Slowly We Turn, Step by Step”……

A beautiful build, very impressive. My real ‘73 is a musket from 1891.  A leather lever wrap will make the lever easier to cycle by making the lever bigger [wider] and giving you more leverage. Makes it gentler on the knuckles too.

A sad little S&W Victory model came into the shop a couple weeks ago. The barrel was cut down to 2", the .38 S&W cylinder has been reamed to .38 Special...

Reaming a .38 S&W with a ,38 Spl reamer leaves an odd shaped chamber. The 38 S&W has a tapered case, wider at the base, so a fired .38 Spl case fired in it will have a wider bulge near the base. Not a safety issue, but if excessively sized too often might show up as an odd crack. It was often done, and if the fired cases get tossed, who cares.

Falling down never a good thing. I'm supposed to be extra cautious about that & I also had surgery last Friday. Nothing over 8 lb for 6 weeks to prevent stitches opening or worse a hernia. Figure that means I'm ok to shoot a lightweight 22 & take short walks as long as don't slip.

I'll get to green pastures & spring one way or another 😁 👍

Hang in there Pard. I fall down going up steps....I need a new back I think so I can lift my feet higher!