B-strings sorta on the track..
Mat Mathias started making Matamps back in the 60s.. Peter Green was probably his most famous client at the time. Later on, Cliff Cooper contracted him to make amps for his Orange Music Shop in the UK. These all said Orange By Matamp on the faceplate and you can see em all over Led Zeppelin live pics as Jimmy Page used them.
Somewhere along the line, they had a falling out, Mathias went into business as Matamp again, and Cooper took over and renamed the amps Orange Voice Of The World and started making them elsewhere. Matamp made stuff here and there until he passed away. In like 1993, a couple of guys resurrected the name and factory and began making what we now call Matamps. The original lines were actually built on NOS leftover Orange chassis and parts from the 70s.. Well some of them were NOS, others were actually POS's that required another $1000 or so worth of work AFTER you paid the almost $2000 to get it to the US before it even worked properly and would stand up on the road.
To be honest, knowing the way Matamp rated their amps, that 100w is modest and its probably putting out a lot more. Their 80w advertised heads actually put out about 120w but then again they rate them differently then US manufacturers do.
If you really want a history lesson, Invalid Link Removed has it..
And they can probably answer any questions about the amp for ya.
How much can you get it for? Hell I know a couple websites where you could turn that thing around for some nice money if it turns out it doesnt suit your style and needs. Id get it for sure.