Inboard turning capacity is 10" over the bed, and 36" between centers. But the spindle is threaded on the outboard side as well, so if I devise an outboard tool rest (I'm considering making an outboard mount for the Shopsmith Universal Tool Rest), I can turn arbitrarily large diameters. It has a 4-step pulley on the spindle and drive motor and a minimum speed of 695 RPM, so a variable-speed motor drive would also be in order for large-diameter stuff.
As a bonus, it's compatible with all my Shopsmith lathe tooling. Both the spindle and the tailstock accept #2 Morse tapers. The spindle is threaded 1"-8, RH on the inboard side and LH on the outboard side. Amazingly to me, Nova sells a chuck adapter that fits both the RH and LH threads -- basically a precision cross-threading job on the ID of the adapter!
Overall, the old girl is in very good shape. But when disassembling the headstock, I found that some previous owner was fond of working on it with a hammer, steel punch, and vise grips. Which made disassembly quite a challenge. Some judicious filing cleaned up the outboard spindle threads. That let me remove the spindle thrust nut and spacer collar, and also mount a regular 1"-8 LH hex nut for use with pullers and such. Everything else on the spindle should be a nice slip fit, but it was still jammed up tight after a couple weeks of marinating in PB Blaster. I finally got it apart today, resorting to oak blocking and 4-pound hammer persuasion on the "slip-fit" parts. The bearings still feel OK after that abuse, but I'm going to replace them anyway.
The various PO dings will clean up OK mechanically, and the ones that can't be removed entirely will be hidden when assembled. The worst scars were from someone assembling it with the pulley setscrew not seated on it's flat on the spindle. That kicked up some pretty big burrs on the spindle OD, but hand filing & polishing will take care of those.
Those big OD burs then formed some scars on the ID's of the aluminum pulley and a couple of steel spacers. They all have 25mm bores, and the scarring is not extensive. So here's my first question for you guys: what's the best way to clean up the ID's of those parts? A round file followed by sandpaper wrapped around a dowel? A reamer? Small drum sander on a Shopsmith? What I don't want to do is open up the whole ID, and lose the precision slip fit.