Hi Rich,
welcome to the forum!
You certainly grabbed that in record time - it looks like it's in great condition.
You've come to the right place for Memotech info - the forum is small - but beautifully formed

Although the number of active Memotech users is pretty small, there is a wealth of knowledge here and a small number of very useful websites, including :-
http://www.primrosebank.net/computers/mtx/mtx512.htm
Where you can probably find anything your ever wanted to know about Memotech (and even more that you didn't)
Run by some dodgy bloke in Aberdeen
http://www.nyangau.org/memotech/memotech.htm
A great place for technical data about the inner workings of the MTX
Home for Andy's great software emulator (MEMU) and his hardware add-ons (Check out REMEMOrizer!!!!!)
Run by ex-Memotech programmer and current guru - Andy Key
http://www.mtxworld.dk/main.php
Hosted in Denmark, but the site is in English
Focused on game conversions and wave file formats for games etc.
Run by Claus Baekkel
http://www.anvil-ict.co.uk/memotech/index.htm
Run by Jim Wills (publisher of Megastar games)
http://mtxinfo.de/
German site, but in English
Run by Peter Ketzschmar
regards
Dave