I had a 46-450 for 3-4 years. It is a reeves drive lathe, there were two version of the reeves drive, one with cables, and one with gears. I had the cable version. That one looks reasonably complete in the picture - the indexing pin is there, and also has the protective shroud. The picture is of the back of the machine, so can't tell some other details. Pretty good lathe for it's day. 12" swing, at least 36" between centers. Heavy as well. Moving it was accomplished by removing the ways and headstock as one assembly and the cabinet as another. They came with any number of power/motor options single and three phase, usually 3/4 to 1HP. Mine was 3ph, and with the addition of a Teco VFD it would go anywhere from 1-2rpm up to 3000 or so.
It also has the provision for outboard turning using left hand threaded faceplate. Parts are reasonably available - I redid all the bearings in mine and ran it for a few years. There are schematics available on Vintage Machinery, and I second looking around at OWWM, a number of folks there have documented similar lathes - I have a post there about getting mine up an running.