I'm happy to say that Ultima 7 appears to now be working with the latest DOSBox CVS build, everything seems to function fine, no graphical anomolies or anything, though it still runs a little slow (even at a cycles = 10000), and upping it any further in-game results in sound skipping (even at 10000 sound skips slightly) - I haven't tested it extensively though so I have no idea whether it does indeed function 100% or not.
I'm happy U7 is starting to work now... Ultima 8 still bombs out right on startup though, I checked the standard output log to see if anything funny was reported and I got this:
Exit to error: CALL: Descriptor type 4 unsupported
Anyway, good job guys, it can only get better 😀