I had a version of this - an MPP product, in fact, in battleship grey - which would take up to a 6x9 neg. It was crude, with a helical focus on the big drum at the bottom in which the appropriate 2" or 4" enl lens fitted (standard 39mm screw). Light source was a 150w bulb and double condensers. Mine was sans box, but I think they were originally intended for military snappers. Some press ones used them complete with a fold-up darkroom - god knows why! Unless one had access to a wire machine, in the good old days, it was as quick to hand your roll of film in plain brown envelope to a bus clippie who'd drop it off in the parcel office at the bus terminal or hand it over to a waiting hack and get his half-a-crown. We also used to use train guards for longer drops, or gull a passenger into taking said envelope ((brown) for the use of)) to hand over to another waiting hack with punter's name on board at destination station. The MPP used to get horribly hot in my cubbyhole under the stairs and smell like rotten eggs, but results were good enough for the Express, Telegraph and so on. As the Ian's have said, what matters is (a) ensuring neg holder is true, (b) good solid baseboard, and (c) above all a good enlarger lens. Mine came with a 2" Wray, which were fitted to Gnomes (made in Cardiff) and were crap. I think the problem was that on cheap lenses, heat damaged the cement between the elements. I had a 90mm Ross Resolux for both 120 and 35mm - 6x6 was max neg size. It was a good lens, generally stopped down to f8. You always have to bear in mind depth of field, and we ALWAYS focused on a sheet of doubleweight paper. Thirty years later, when I has the space to set up my own darkroom with a Durst AC707, Philips PCS 130/150 and an weirdo cold cathode heap for 5x4 which I bought new from Rob White in Bournemouth, I had a Minolta 5cm inititally, which was poor, changing to an El-Nikkor at 50mm and Schneider Componon-S 90mm with Rodenstocks for 105mm and 150mm on the beast (it looked like an agricultural version of a ZoneVI) - the latter lenses were superb, but I've either lost them or flogged them on . . . oh, the mistakes we made when we were conned into digital photography . . .