Next, is he buried in a cemetery? If not, all you need is a Bob Cat fitted with an eight inch auger, bore two holes to 20" deep, trim to a rectangular size to fit, remove the auger and fit with a line, lasso the stone, drop it in, align the stone and fill in and tramp down, and that's it. The local SCV managed this at Vicksburg ten years ago when we placed some 77 stones in Confederate Rest. Took us two days.
Here in Reno, I found a Confederate Veteran, a batchelor who died in 1920, no marker whatsoever. The Cemetery management filled out the required paper work for me, received the perpetual flat marker, and placed it at no cost and no maintaince fee. Their rationale was that these fees were not in place when the Vet died, nice.
If he is in a Cemetery, I'm sure the costs associated with this labor shouldn't be that much.
Good luck,
George Martin