Ampeg SVT-48HE 4x8" Classic series cab?

Doing more research I figured out I have a SVT-48HE cab and they just put the serial number sticker over the model number

I got what I think was a great deal today, an Ampeg SVT-3 Pro, a SVT18 and the piece I can't find any information on, an I48HI (that's i48hi) 4x8" Classic series cab. Ampeg doesn't have anything on their web site, and google turned up very little. Does anyone have any information/specs on this cab? The guy at the store said Ampeg didn't make many, mine has a serial number less than 10.

I would like to trade the SVT-3 for a SVT-4 and biamp the cabs, but I'm considering just designing a passive crossover to try to protect the 4x8. Or I might trade the 4x8 for a SVT-410HE... (Is it a sign of a bad case of GAS when you are scheming to trade stuff before you've even paid for it?)