well guys you have almost talked me out of selling the stack.tomorow i will go over and pull the chassie out and check for the date and inspection sticker.and post them here with what ever the inspecters inicals are along with the s/n. belive it or not i am a profesanal photographer. an i just took a few quick jpegs of the amp with out checking them out before posting them on e-bay. so if i do a documented shoot is there anywere to post them on this site or others for research use? this amp has two of the biggest transformers i have ever seen and in the back is a recested slot like a screw head marked as a lock for reverb. but i see no reverb pan and there is no control switch or knob for reverb control. another mystery is the large knob ..the last on the right.it looks like it was added later. I was told by a hamond jocky those were done at the factory..but that was a guess.who wants to put their trust in a guy who moves a B3 around for a living..he cant be that smart. unfortuneitly...and this is the truth i bought the whole unit from a young widow whos husband died so i cant ask him.and she sold me the whole stack for $200.00 yes i know my soul will burn in hell...the only other clue to the stack is the old band name stinceled on the back of the speaker cab '' MIDDLE EARTH '' the logo has the trade mark and the tubes are 6550,s and so i think its post 1969. if anyone has recomondations on speific photos e-mail me and i will check this form before i go out tomorrow. Blueduck Chuck