Finally got hold of a SCP-55 for a halfway reasonable price!
After messing around with card services, it's working great in DOS. Default resources are IRQ 5/IO 330 which is fine, I have the SB16 at IRQ 7/IO 300.
By running a short cable around to the SB16 line-in I get digital sound and the Roland music through the built-in speakers.
The only downside as compared to a external module or daughterboard is that the IBM socket & card services take around 30K of conventional memory, and it also seems to require C800-CFFF to be vacant, so that's another 16K of upper memory gone. This machine also requires memory-hungry SCSI drivers for the CD, so I could see it being an issue for those few real-mode CD games with MIDI.
Overall though, it's really cool to see a legit Sound Canvas in this form factor. My CT1770 has the hanging note bug so an external module or DB wasn't an option. Might try CardSoft later to see if it supports the IBM and has lower memory usage.

