I don't know as much about the Coliseum series as some others, but I'll try.
Black and red puts it mid-to-late seventies, I think. Coliseums were rated at 300 wrms at 2 ohms, IIRC.
The cabinets I think are a little earlier, around 1974. Should be model 118V. In fact, that should be on the jackplate on the back. I don't remember the power handling, but they were pretty impressive for the day, not so much so now.