Looks to be an S15B or the smaller 1x15 Alembic cab in Mill Valley, CA. Facebook Marketplace. They added a crappy speaker grill but that can be removed. I see dual XLR connectors on it for chaining together with another cab. If I was closer I would be on this for 250.00
https://www.facebook.com/marketplace/item/1104523341008382?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3Af44094fa-43b0-4094-9584-46006707ed0c

that chicken wire grille is a real fasion statement.  wonder if it's acoustically transparent? 

good luck to all!

Bet he would take 100 for it.

That's hardware cloth, not chicken wire

Seller seems unaware that this is a front-loader. 

Bill, tgo

There is also a 1/4" jack in the upper left corner of the front panel so who knows what wiring lies within.  That screen, and for that matter those spring loaded handles, should do some fine rattling once you find the resonant note.   

Jimmy J

I remember that ALEMBIC A15 cabinets were sold at the old Alembic 60 Brady St. location back in the mid 1970s. The metal grill hardware cloth was inclusive in the design as sold by Alembic at the time. Mine have no handles and have banana plug connections.   I also some actual WOS design units.