[Arran]

I have the updated version of one of these, it's an S-42A, the difference being that it uses push pull #47s rather then #45s. The two copper cans are/were wet electrolytic filter caps, inside the two square cans, one is for the audio interstage (I think) and the other contains and assortment of paper bypass capacitors. For the filter caps you can use 10 uf 450, radial lead, electrolytics on a terminal strip if you have to, for the bypass caps I would recommend using plastic film caps of the appropriate values, and voltages, so you don't have to mess with that can again. When I get to my S-42 in the restoration docket I will probably put poly film, or motor run caps inside the copper cans, speaking of which some of the larger motor run caps come in metal cans with threaded bases like the old electrolytic cans, Mouser sells them. Like many pre war radios one of the filter caps has it's negative side connected to the H.V center tap of the power transformer, whilst the negative side of the other can is connected to the chassis, but I would double check the schematic.
Regards
Arran