You need to test the signal generator output at 1MHz (or less) to be sure of attenuator type.
For? a 8920A the Firmware is in ROMs. I don't know of an image available.
The memory card slot in the 8920A takes "Epson" style Ram or ROM cards. These are NOT PCMCIA cards. They use a side contact connector a bit like an edge connector covered by a shutter. Similar cards were used in the HP 48GX calculator but I don't know if they are compatible. I have heard of clone cards being made (certainly for the calculator) but have not seen firm evidence of them working in the 8920A.?
Even if you buy an HP RAM card you still have the problem of writing to it. (the ROM cards are one time programmed)
The best option is to load the software through the serial port. See the thread on here about reading configuration data for some ideas on how to do this. Basically you set up the 8920x to receive a file as ASCII text as if you were typing it at a serial terminal.
Good luck.
