The narrower GP7 combo was available as the 715 which was rated at 100w, it didn't have a DI and it had an 8ohm speaker so there is only one speaker socket. There was a 200w version, 715S, which had a DI and a 4ohm speaker with two speaker sockets, this was also available as a sleeved head called the AH2007S. Also a 2x10 combo, which I think was 200w and called the 7210.
Trace Elliot also had the 200w GP12 1215.
The build date should be on a label inside the head section.