Still want to try making these covers out of some walnut I've got lying about (much to Clive's amusement) - no reason why a decent hardwood shouldn't work, eh.?!
Re the T-slot cutter for the sake of others I have done plenty of these but the cutter needs to be spun at 600-1000 RPM.

Going to be a very nice machine, Keep up the good work and vids.