I think that I have have it now.
What I thought was the Wallace crest - Dexter arm in armour, embowed, in hand a sword.
was actually Kellett - Armed Arm Embowed, Garnished Or, Holding In The Hand A Baton.
The strap and buckle (Scottish heraldry) is actually the Royal Garter and the cross is the Garter star.
The motto is still confusing because the Kellett motto is Feret ad astra virtus (Virtue shall bear to the stars) and the motto on the flag is Auxilium ab alto (Help from on high).
Well that kept me occupied for a while.
Maybe if I had spotted this yesterday I would have been ready for it...
https://www.bbc.co.uk/news/world-europe-64869814