indeed Rob, i had my nun-chuks with me and all!
Steve, it's a bit of an oddity i think. it doesn't actually say Matamp on it anywhere! there's a wee sticker under the chassis with the name Paul Tribe and an address and phone number. Colin said it's a shop near to Matamp who commissions small numbers of amps from the factory. there's a plate with specs, serial number and model, which says it's an AB15. so it's seems to be similar to a Vox AC15, just with a full set of tone controls and a master volume.
i'm not bothered about the lack of branding, fact is the amp sounds good, and anyway, it maintains an air of mystery around it! 8)
hoping to get it cranked up this evening, i reckon my Mississippi Queen Les Paul will sound great through it, and my Gibson Blueshawk.