When I was looking at pumps and pullers a few years ago, I noticed that some of the OTC stuff looked identical to Power Team. I am almost certain that your ram is the same as a double acting Power Team RT1004. But I don’t know if Power Team offered a full track press. You could contact them and ask if they sold the C frame and tooling, and see if it is the same as yours. They sell a pretty wide range of hydraulic tools.
I just did a brief search in an attempt to see if Power Team did in fact make a track press, and I came across a Tuxco track press. The C frame on the Tuxco looks similar to your OTC, and some of the other products appear to be the same as Power Team. Maybe call Tuxco and see if the dimensions and tooling are the same. A lot of this stuff seems to be made by one company, then half a dozen other companies buy it and print their name on it, then add a significant markup.
Does this C frame look similar to yours, aside from the guards and different ram? It’s their 100T model. Maybe see if they have a drawing with dimensions.