Our friends at Lettertypen in Berlin have quite a few old presses, all of them operational. The biggest one of them is Johannisberger Schnellpresse from 1924. It prints sheets up to A0 format, 88×126cm (i. e. 35″×50″), with manual feed but automatic delivery. See here for a list of other equipment our combined workshops have: SchriftDruckPapier (in German).
After a long search, he recently found a few missing parts and last week Daniel ran the first sheets through the press. Watch it here: