I seem to remember that he did some sort of voluntary work but I can't remember exactly what that was
Nick
this factor could well be part of the award - although not all of it. As you rightly say, many do a thoroughly good job without any award, and that bit extra in their own time can often swing the award. Much respect to him in any event.
Service records are available to NOK - your Mum in this case - at no cost. There's a unit at Cranwell that deals with them all and a simple (ish!) form to fill in. I'll try and dig out the details - I recently got my own (extensive!) medical records which (bizarrely) my GP couldn't get to through the NHS.
Edited to add:
Gosh Nick I'm more efficient than usual today!
Here is the link to the form you need. You can fill it in on the computer but ISTR you have to make hard copy to sign (or Mum to sign) and send off. The Cranwell address is also on the form.