Nice grinder. It looks like one of the older, stouter ones. And in good shape still. I put a VFD on my square wheel, and it works great. When I was running it single speed, the 10" drive wheel that comes stock on these was too fast for me, so I fitted a smaller drive wheel onto it. (7".) This necessitates drilling and tapping another tooling arm hole toward the front, so the arm can come forward to compensate for the added belt length up front. I learned this from Ed Caffrey, who has a few tricks you can read about over on his website, about improving the square wheel for knifemaking. He makes a platen which would fit on your grinder, styled after the original rotary platen. Or you can get plans to build your own.
I'm sure you're fine with using it how you got it for a while. Just having a "real grinder" is such a huge step.