I have a 5" Richmond dividing head with the drive spindle etc for differential indexing (but alas no gears) I'm going to move to a Divisionmaster electronic system and will need to strip off all the differential indexing drive gears etc to mount a stepper. These mods will mean that the dividing head will never go back to what it was! However if someone has a similar quality 4.5"-5" dividing head that's already had this drive gear removed and actually wants one with differential indexing capability I'd be happy to consider a swap to avoid unneeded vandalism!
Regards
Charles