In reply to Durbs:
Ah, that will have been what Route Adjuster was on about. I see. Maybe I need to play with Kodi's auto-DJ, as that's all I'm really after, if the player side, leaving the manager elsewhere.
I'm coming around to the idea that I don't actually need Windows on this machine, since I don't run any Microsoft software on it. But something is making me resistant, and I can't put my finger on it... Possibly because I've invested a fair bit of time getting the thing running nicely. Until the licence issue...
I may go for that Linux Mint, Wine for MM, and then use a standard Kodi install. Or I may not...
Thanks to all for the suggestions: further suggestions very welcome.