I used to own the Rabco, the difference being that it was mounted on a Thorens table. Be very careful that you mount the arm absolutely perpindicular. The rest is easy. Watch the arm length for the cartridge used. The stylus must match the center of the spindle. My Rabco was a cantankerous beast. First the good news; the battery lasts for several months. The bad news; the tonearm rings. You need to find a lightweight dampening compound. I solved the problem by building a balsa wood arm that I laminated out of thin strips of wood, then built the arm into a rectangular cross section that I filled with foam rubber. Nowdays I'd try a spray on dampening compound on the underside of the arm. The other major weakness is that the contacts to activate the motor tend to collect dust or oxidize, and the arm stops tracking properly. Your milage may vary.
By the way, the late Mr. Papier of Triplaner arm fame got his start modifying Rabco arms. Good luck. Please let us know how the project turns out.

Steve