Jeez you've got good eyes. I took a pic of the inside and, yes I can see a connection at 45 degrees, although I can't see it on the other side.
However, your (welcome) suggestions didn't yield an S so I went ahead and mapped all the keys. And at last I found an S. Jumping the Space and F10 should do it!
In case this info is useful to anyone else:
- there are 8 rows and 20 columns (although I arbitrarily assigned the names 'row' and 'column' of course so there could be 20 rows and 8 columns).
- 4 of the columns only have Shift, Control, Function and Alt assigned to them i.e. one column for Shift, one for Control etc.
- I have every one of the 108 keys mapped if you're interested!
thanks for the help chaps.