Thanks for the reply, and sorry for my tardy one!
I didn't know Dick W did vids - have to find them.
I've sent you an eBay message as suggested - thanks.
Having managed to get my 422 to complete it's cycle, it now won't do anything else!
All the mech seems free, the keys won't press in (although they're all free as well), and it won't crank. I've removed both of the side locks, also hold the bar that prevents the register being cranked while the drawer is open.
Is there something I'm not doing right? Still a newbie with registers although I've just successfully completed restoration of a National Class 21 electric machine from around 1960.