Congrats on your family heirloom and welcome from Virginia
That is a nice one for sure OP, and with family provenance too. One suggestion beyond obtaining the Factory Letter of Authenticity would be to gather as much information on the family members who owned it before you. Not just their birth and death dates but any relevant stories someone may have in their personal archives about what grandpa did for a living, where located, any law enforcement duties....in other words....anything before being lost to history.
I am not a reloader so I commend you for looking into it, especially for this caliber. I had my 32-20 WCF Hand Ejector for almost a year before I received a very nice Christmas present of 3 boxes of HSM (Hill States Munitions) "Cowboy Action" 32-20 newly factory made 115 grain ammo. Literally I had searched several sources on line for a year and not found any brand, at any price and my wife found these. All she said in reply to my question of how much was "Don't ask!"
A couple other things about these guns, mine is serial number 105093 and it shipped from the factory in October 1921 per Dr. Roy Jinks, the S&W Historian at the time I asked. According to information in the SCSW 5th Edition, the cylinders on this model gun started being heat treated at serial number 81287, so you are good on that account. Another thing is some of these guns had a "divot" (like in golf...a chunk of metal removed) in the top strap. Mine does not, check yours to see if you have a divot. Unfortunately I cannot for the life of me recall why the divot was there on some guns, or if it is detrimental to anything at all, but the real experts may be along to enlighten me (us).
One last thing...most of my S&W revolvers do indeed shoot to point of aim, but this gun shoots consistently high and slightly left so it really well could be the 115 gr ammo, but I do not have alternatives. The HSM ammo is brand new, manufactured using Starline Brass as I understand it, and if you see it anywhere for $1.00 per round....grab it fast.
