I'm sure someone has info on this...

One can't really tell much without opening the back panel, but I will make a guess based on the photos provided in the auction listing, and typical system configurations from the period. It would appear that this is a PDP-11/23+ system. This is based on the basic "Micro PDP-11" medallion on the front panel, and the 2-port cab-kit, which is standard for the 11/23+ only. (11/53's, 11/73's, and 11/83's have single-port cabinet kits.) I see two 4-port cab-kits on there, which, based on the era is most likely a DHV11, but it could be a pair of DZV11's as well. There is a lone connector in one of the "A" slots, which could be just about anything. It sort of looks like the LPV11 cabinet kit with the 37-pin connector, but that is just speculation. The RX50's tell you that there should be an RQDXn controller installed (most likely an RQDX2) which might also indicate the presence of an RD52 or RD53 disk drive behind the front bezel. It probably has an MSV11-P memory card installed, for 512K of ram. The BA23 chassis looks to be the newer style, with black buttons on the front panel. Hopefully this indicates an upgraded power supply harness. Again, these are just the "most probable"; someone could have done some upgrades, but without a peek behind the panel or more information from the e-bay poster, it will be impossible to say for certain. T