Crosley used 6B5 for output tubes. Model 515 uses the same tubes but doesn't have a 75. Might be a good place to start?
Norm
:Tubes are 80, 6b5, 6d6, 6d6, 75 and 76. Not sure on the 75 but I think it is since somebody wrote 75 on it around the bakelite base and I tested it as a 75 with good results. It has a three stage tuning condenser with stamped writing on it......Reliance & stamping co.
:chicago-u.s.a. pat. no.576828-1591317 others pending 1912. It has four knobs with the same arrangement as my detrola 106. The transformer is a halfshell mounted horizontally on top behind the volume control. It has one of those caps that is a dry electrolytic box type. One of the neat things about this radio is that it has one of those acorn looking things in it which has to be a bias cell(never actually seen one up close). the dial is the round type with glass covering it. says kilocycles standard boradcast on top and ameture & police/megacycles shortwave megacycles on the bottom. the center by the needle has germany england italy france and argentine so. america with pictures of the countries flags and their shield with each country. the dial isnt the strung type, the dial lamps are behind a big round piece of off white plastic, this round plastic(6 or 7 inches round) is turned by the dial knob directly by pinching it between two thin pieces of round metal(brass?copper?) on the knob shaft. this plastic is behind the face you see from the front. there are two tall cardboard coils with trimmer caps on top of them to the right of the tuning condenser