@Madd-Matt
I don't have a card, I'm running my old Amiga setup through WinUAE (booting straight off the old HD). All I need to be able to do is come up with a Kickstart ROM image that has all the modules (or as many as I can get) in it that I need for this setup. Thing is there doesn't seem to be any readily-available ROM module manipulation programs out there. Sure there are programs to load them resident at boot time, but that's not what I'm after.
@Tickly
Hmm, maybe it isn't possible then. This is starting to look a bit bleak. :-(
Say, I just remembered something. The other day I noticed a file on Aminet for making a FlashROM module that plugs into an A500. It's designed to have 1 MB of space on it (don't worry, the docs explained it and it is possible to have more than a 512KB ROM in any Amiga, as it was done that way for at least one model). What I did notice is it mentioned that anything could be loaded into that second half-meg, including reboot-resident modules like the OS3.5/3.9 ones. I wonder if anything like this could be possible with WinUAE?