A pretty competent auto electrician has told my garage that you can’t fit secondhand n/s rear  window motor to my scout , does that make sense to anyone else  .? , I got this secondhand from the garage , wonder if he meant  you can’t fit any similar make that physically fits instead .? Don’t fancy forking out £270 incl vat on the part .I maybe should add we have just fitted a new door lock too .

This sounds like "I don't want to fit a secondhand window motor" rather than "You can't ...".  There are several threads on here regarding exactly that activity; main issue seems to be tackling and replacing the rivets used to secure the protective metal inner door plate - the pop rivets are (I understand) not a common size.

 

I wouldn't have thought a motor module change would need removal of that panel?

 

A secondhand module with identical full part number, from a car of same age should be OK, I would've thought.  What age is the car?

 

2008 , I think I will order one and try it .

I think you'll find the part number as indicated here, possibly minus the SK3 suffix (not always printed on the part number label, in my experience of other VAG models). Eyeball confirmation would be wise before spending.