>what it is: totally unofficial, no guarantees etc. etc.

>The snapshot is available from

>   ftp://ftp.ntnu.no/pub/NetBSD/i386-1.3_ALPHA/

Just tried "upgrading" with this to no avail.
Looks like any attempt to run fsck just gets a mount_ffs usage
message.  fsck_ffs seems to work ok, so I tried 
sed 's/fsck/fsck_ffs/g' upgrade > ug 
and ran that.  It gets much further but still bombs with something like

checking wd0a
/dev/rwd0a: ...
Mounting root on /mnt
Done

Copying new fsck_ffs to /mnt Done
Re-mounting root partition read-only...
/dev/wd0a: filesystem not clean; please fsck(8)
Done.

checking the rest of your file systems...
Usage: fsck_ffs ....
FATAL ERROR: ...


so I guess that's not going to work :-)

--sjg