I've finally done it, after weeks of being a cheap bastard and waiting for the right one, I managed to get myself a JVM410H on fleabay this weekend for the bargain price of £490. Very minor wear to the tolex, but easily sorted, other than that, looks pretty good. Guy says it's not had much use, just selling it on as he can't be doing with carrying heavy amps/heads around anymore. Fingers crossed it's all good. I'll report back once I've got it and checked it out. Need to start looking at tubes etc. now, so very exciting.