So there are no specs set out for other versions but the code suggests that other bands can be catered for or were contemplated.
So LPF, the BPF after the tx mixer and the receiver input BPF would need modification. And some code. Anything else? And the code says to use a different IF so different filter crystals etc but why not use 9mhz like all the other bands?
Also, any reason why one of the display lines not already with dual purpose couldn't be used for a second keyer input to run a paddle/keyer?