I've got the cassette below - it'll go to a charity shop if nobody wants it. It plays excellently and the cover's in great shape too. There are two stories:
"The Curse of Crystal Mountain" and "Dragon from the Lost Valley"
PM me if you'd like this and I'll work out the cost to send to wherever you are in the world, plus whatever the Paypal fees will be.
Most-wanted MOTUC: Granita - Hunga the Harpy - The Melog - Dylamug - Sprag, Sprocker and Spritina - the Twiggets - King Ahgo - Filmation Grizzlor, Mantenna, Leech, Modulok and Multi-Bot