35mm projector close to working

I lunched with Derek today. He's been tinkering with my old Acme portable 35mm projector and thought he had it running. However, once I arrived, it was only moving slowly. He suspects that the belt needs changing/adjusting. I experimented with the threading path and think I'm close. The most confusing part is the threading of two rubber rollers which make up the coaxial twist between the feed and the gate. I found a similar one on ebay but it has one less switch and doesn't have the work light inside. The ebay item doesn't have pictures of the patent information panel on the outside of the case either. The three prong power cord is missing and Derek has had to make due.