Apparantly it's a Performa 630. This is the reply I got:
Word for word!
EDIT: I have now realised that the person sending the email may well have done it from a Blackberry or similar web-enabled mobile phone, so spelling and grammar errors may just be due to high-speed texting or something similar...
I may as well go and get it, I doubt whether anyone else in this area would be too bothered and it is a 68k Mac after all. My collection doesn't currently include a 630 so I may be able to accomodate it somewhere...