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Tube FM front ends tend to go bad easily, if the tube gets a little low on emissions. Also many such AM/FM sets tended to spend most of their life on AM, and the FM tube would go bad due to "sleeping sickness" (the cathodes being hot but no current being drawn does bad things, but a few tens of microamps of current is enough to prevent that, connect a 100K or so resistor across the B+ part of the band switch on such an all tube radio, not this one though). But the transistors won't have this issue. But transistor FM RF front ends did suffer easily from signal overload, intermod products creating interference on weaker FM stations (though I've been told that increasing the current thru the RF transistor will help). Living 14 miles line of sight from NYC's Empire State Building's FM broadcast antenna farm brought this issue firmly in my face... Tube front ends usually did better on this.
Tube line up is probably like that in an AA6 AM radio, but the extra 12BA6 being the 2nd FM IF tube (and it may be a 12AU6). If they were skillful enough, they might have been able to put that 2nd FM IF tube to work as an AM RF stage, like in most AA6's.
Not using a tube FM front end meant that they would have enough heater string voltage left to use a 35W4 rectifier. Which might have been cheaper at the time than a SS rectifier diode.
GE used the same or quite similar audio output transformers in their solid state hot chassis radios as well.
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