Ill check the battery before powering it in. Its been unpowerd for at least 10 years so they probably need to be replaced.
I would snip the battery leads or desolder if you have very good soldering skills. I would not spend much money till this old girl at least jogs.
You may need help with the run-chain jumpers to get it to jog. Looking at the back wall inside the controller, you should see the System Terminal Unit that should be a DSQC124 or a DSQC138. Can you verify which one?