HELP! My IIgs ProDOS boot partition is corrupt!

["Rodney Hester" <rod3@mindspring.com>]

OK, so I did a very stupid thing.  I did a power-down in the middle of a
GS/OS boot.  This is a Bad Thing(TM).

After powering back up a few minutes later, GS/OS 6.0.1 started to boot
normally, until it tried to load GUPP, at which point it failed and said I
had to restart.  I could reproduce this at will.

I shift-booted, came up normally, and deleted GUPP, thinking it was the file
I had corrupted.

After rebooting, the IIgs steadfastly refused to boot from my ProDOS
partition.  Finally, I booted from the GS/OS System floppy, to discover to
my horror that it no longer recognizes DEV1 and offered to initialize it.
Urm, no!

Is there anything I can do to repair this partition short of initializing it
and starting over?  (I am, needless to say, not thrilled about that option,
but will do so if necessary.)

Rodney