It's most likely an early Model 1042. It has babbit bearings and a vertical countershaft. It could have been a V42 (which is a vertical countershaft babbit bearing 10F) but 10-247 would be an early left gear guard part number. 10D and 10F would have had one with part # 10D-247. Plus it has the fabricated change gear guard which only appeared in the Atlas (and Craftsman on the 12") in about 1935 & 1936. It isn't a 10A, 10B or 10C because it has both back gears and change gears. And it isn't an upgraded 10E because the 10E as sold was a stripped down 10D that you could later buy the rest of the bells and whistles for and it would have had 10D-247 on the left guard. It also has the early symetrical (nearly square) bed legs. And it has the early wagon top compound slide with the early small wheel instead of crank and the early tailstock (all straight lines instead of curves).
The two solid handwheels on the carriage are not originals. Everything else that I can see seems to be original.
If you look at the right gear guard, you should find 10-246 cast into it. Somewhere on the headstock you should find either 10-2 or 10-2A.
If the numbers "01575" are stamped into the top of the bed down at the tailstock end, that's the serial number. Early models of the 10" (and 12") would have had an Atlas or Craftsman nameplate on the back side of the bed with the model number stamped on it. But these seem to mostly be missing.