Error 19 on mounting gprootfs?

Thanks to a very helpful member of this community. I am a lot closer to
restoring this system but I now seem to be stuck on an error 19 error on
gprootfs. Research points to a controller error but another virtual disk
image boots and runs just fine. So that points to the virtual image or the
root partition. Repairing a VM disk image might be outside the scope of
FreeBSD but maybe this is something someone has seen before.

If it's not repairable what would be the best way to pull all the parts
from /usr and /var to a different disk image and get on from there? rsync?
tar? Not eager to relearn how to set up postfix, nginx and friends after
all these years.

-- 
Paul Beard / www.paulbeard.org/