My machine (the small one) is a Grizzly G-1550. Identical to your's with a 1-1/2X8 spindle nose. A big issue is the drive belts. I use Dixie Bearing as a source, they were all over the country when I was in the service. 5M710 or 5M730, depending on where/when it was built. You need at least one spare, two or three would be better. They're cheap enough and quite useful. . . I ended up acquiring an assortment, the 5M series pulleys are easy to make with a threading tool at a 60 deg V.
I eventually went with an Atlas/Craftsman 12X36 because I was cutting down brake disks to make railroad wheels. (7-1/2 Ga) The Griz was too small to swing the rotors. Other than a full Norton threading gear box and the larger swing, the Griz actually fits what I do better. One adaptation I made was a planetary gear head to fit the power end of the spindle. The ~3:1 gear ratio gives me ~40 RPM on the chuck. My web site is down, the host changed software and many(most) of my pages didn't survive. The article is posted in several locations, I lost the links in a crash a couple-three years back. (My last stroke(6) left my mind a little fuzzy, I couldn't rebuild the site) The only parts acquired were from an old (GM?) automatic transmission.
The HF version is a little more rough than the Grizzly, but makes a very good machine in itself once tuned. Being used, your's may have the tuning done. The only advantages to a larger machine is the larger swing and a couple of powered features. But for smaller work it actually is easier to use. There are a couple of ZAMAK fittings that you would do well to replace with steel or brass. ZAMAK is sensitive to an industrial solvent that still shows up occasionally. CRC Brake Clean being most likely. The base chemical has been outlawed in the States, but derivitives are still used in some applications. Making the threading lever isn't that hard.
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