That link was very useful, I reviewed the keyboard functions and mapped a few extra keys that I used frequently with my previous remote.
'b' maps to record function 'schedule recording timers', which is a different function, It does not directly enable a recording.
Some forum posts suggested that in previous versions of XBMC, the keyboard letter 'g' was for the record function.
The current kodi keyboard layout has no function assigned to 'g'.
I installed the keymap editor add-on to Kodi, then editing the default keymap.
I found 'record' within the PVR functions, and mapped to the fancy red record button on my new remote.
Record function now working!
Thanks for your help, I wasnt expecting such a quick response to my post.