No. 3, 4 & 5 SSM
 

I posted this question in the technical section, but I thought I'd try here too.

I am trying to determine if a drive offered to me is a No. 3, 4 or 5. What is the easiest way to distinguish them? Also, are the gimbals the same? I need to see them tonight so any info would be greatly appreciated.

Can the rotation direction of the drive be changed, and if so, how?

Also, what would be a fair price for the drive and for the gimbal if they are in good condition?

Thanks