*Edit*
I need to read the above posts more, from searching it looks like a 300W out of a combo as stated above, but the pics of 7215s off google look different so it may be an earlier model.
Found this in another thread here
http://www.talkbass.com/forum/showthread.php?p=7151745:
"I've just aquired a beaten up old GP7 head from what i think was the combo 7215-7 300watt bass combo
Having looked inside it seems to be a popped fuse, but a friend's looking at it for me just to get it in good working order. there's a date on a PCB inside that states 06-05-99 which makes it nearly 10 years old, and also means i can throw it a birthday party
It outputs 300watts at 4ohms, so my plan is to build a nice wide 2x12 combo, and leave a space to get myself a green rackmount light for it, just to keep it trace-like. and then build an equally wide 15 to sit under it and pull it down to 4 ohms, meaning i should have a nice fat looking, fat sounding stack!"
I would try posting the pic over on that thread, the TE guys may be able to help more.