Alright, so if anyone tries this, don't do a repair. I reverted back to my original VHDs after trying that.
After reverting, redoing the hal.dll and ntoskrnl.exe from the install media, I changed the Virtual Server 2005 drive configuration from SCSI to IDE and it booted.
So maybe ShadowProtect was helping me all along by providing a generic IDE driver for me, when I was stupidly trying to boot my recovered system off of SCSI under VS2005. Long time VS2005 users will know why I was trying to use SCSI...
So, I'm still not 100% done, but much closer now.