Despite my simply feeding Ghidra the flash image and specifying the wrong architecture, it seems to have worked.
However, learning to use Ghidra looks pretty daunting and I don't think I have the time to do anything serious. All the stuff I know to do and then some is already implemented in Ghidra. Unfortunately I don't yet know how to access what I want.
For example, 0xb34e() has an infinite loop following a series of function calls suggesting that it is the main loop when the DSO is running. However, I can't figure out how to walk back up the call tree from there.
I'm certainly impressed by Ghidra. I had not known of it before, so it's been a very valuable education. I can see lots of uses for it, but I think I need to start by analyzing a less complex program.
Have Fun!
Reg