You are correct in that when you are finished with a Mosin you have a Mosin.
But you see, that exactly what many men and women want.
At least here in Wyoming I have a good demand for such things.
I make muzzleloaders for a living, and I earn about 85% of my wadges on them.
When they are done you have a flintlock or cap-lock. If someone wants a Weatherby or an AR-15 they don't order a flintlock. Same with all lever actions, Ruger #1s and so on.
Same with Single Action revolvers. They are not ever going to be able to fire 17 rounds without a reload.
But that has nothing to do with the market for them.
I find that with M/Ns I have a lot of business making nice shooters from junk, with rusted out bores and broken stocks, because every gun shop in this state was selling the low grade M/Ns a few years ago for $60-$69 each. There are a
lot of them around now.
If the bores are good (about 1 in 3) I have call to restock them with laminates or plastic. I get a lot of call to make new bolt handles and install safety rings for scope use as well as some call for mounting scope bases and rings.
In doing this we get rifles that compare to the low end commercial guns in cost (like the Savage Axis) but the owners seem to want the Mosins more then they want an Axis. I don't argue with them, but I do tell them about the Axis and the Ruger Americans as well as some other options. if they want the M/N instead, I am all for it.
That one in the photos was rusty and the bore was a 100% loss and about 1/3 of the toe of the stock was gone and the handguard was split and o0ne half gone.
So it got a rebarrel job.
I had a piece of walnut too so I made a new stock. At that point I thought I may as well pull out the stops and do the rest so I made custom sights, a barrel band front swivel base, installed a per-war style butt, a steel grip cap, and an ebony tip.
Yeah, its a labor of love, but I am not alone. This is the 3rd one I have done this nice and the other 2 were sold before they were finished.
I was going to do a 1910-1920 style carving on the stock too and cover the action and magazine with engraving, but if I go that high-grade I may not find a customer that can afford if even if I only work for $15 an hour.
So I'll stop it here and see if someone wants it. if they do I will offer the other decoration and see if they want that in addition.
Such rifles are not wanted for just an ability to throw a bullet accurately, even if they do so super well.
They are wanted because they are cool!