CTW,
Good morning! Fine looking piece! Unfortunately I can't tell you much at all on your nice rifle. Almost all of my literature is PA based, with only minor footnoting of where a certain few families or undertudies may have taken their trades as they left PA.
I know people who may be much better studied than I am re: your questions. I am curious as all get out though, about the markings relating to 'machine shop'. I do know, that just like here in PA, the sport of shooting smoke makers existed in small pockets with nut case fanatics (like Savage collectors
all over the country. And that there has always been and always will be a keen market for a fine longrifle. There was still a man crafting lock, stock, and barrel here in a quaint little village about 20 miles from home when I was adolescent. (I have the exquisitely pleasant memory of watching him rifle a barrel with a wooden pull mill, and shimming his cutting edges after each pull with little pieces of oat straw!!!) That was long before the black powder craze began in earnest in the late 70s early 80s over most of the country...and world!!
With the markings on your rifle, the likes of which I've not seen on any of the period guns from the PA Golden Era, I can only hazard a guess your piece was made by an individual similar to old Mr. Gansel of my youth. A die-hard devotee, who probably did die, thinking he was the last of his kind.
Additonally, I can only guess, but perhaps your barrel inscription would 'read' this way?
"Proof test, 120 gr. fffg Soft ball" ?? or 'single bump'? I know the rifle I'm shooting now was 'tested' by it's maker, and he found it shot best with 80 grains of 2F with a 495 ball and .013 tick patch...but only because he told me so.
(I subsequently discovered I can do much better with 80 grains of 3F behind a 490 ball, and a .017 soft linen patch.)
Very handsome piece you've got there, in any case!!
And any more, any more..than 60 paces is let'em walk distance for me. My rifle is certainly capable of more...my eyes aren't
ed