Tascam MSR-16 Tension arm roller The Half inch machines use

The Half inch machines use a tiny bit longer shaft

This is the idler rollers and gear from a tascam 133 but may have been common in other models at that time using the slightly larger tyres

There are three types of connector on is on a pcb like this

In old machines this grease dries out so the drum unit  gets stuck and springs fall out etc etc

its a part that would not go wrong but maybe your missing a motor and need this as well

Tascam MSR-16 Tension arm roller The Half inch machines useTension roller for the MSR 16 1 2 inch I have left these how they arrived but would recommend a good clean and buff with a felt polisher price for 1