Rare MM cab spotted on eBay

Item 290863011482
To me it looks like model 112BX EVM. As the 'B' suggests, this was originally created for bass use (no doubt as a companion to the B-120 or B-100 heads).
In comparison, the 1x12" MM extension cabinet for guitar (model 112X) is open-back and wider than the 'BX' bass cab.
One of these (the 112X) sold on eBay in January and I have asked permission of the seller if we can use his picturs here on the forum. Hopefully he'll say yes and I can post pictures.
Cheers,
Lars Verholt