You could instead the scripts that are part of etcmanage:

  cvs -d acert.ir.bbn.com:/cvs/etcmanage co etcmanage

They will do in-place upgrades when run under the to-be-upgraded
system, but don't yet write boot books.  They are a little
under-documented, but pretty well commented.

  Hmm -- I do have /etc/raid?.conf files, but I see at about that point
  in the boot process 


          raid0: RAID Level 1
          raid0: Components: /dev/wd0a /dev/wd1a
          raid0: Total Sectors: 829440 (405 MB)
          raid1: RAID Level 1
          raid1: Components: /dev/wd0e /dev/wd1e
          raid1: Total Sectors: 115647232 (56468 MB)
          boot device: raid0
          root on raid0a dumps on raid0b
          root file system type: ffs
          raid0: Device already configured!
          raid1: Device already configured!

  which suggests that they are auto-configured.

It does look that way, so after you set the raid sets to autoconfigure
you should have moved those config files aside.
'raidctl -s raid0 will' show you if it's autoconfigured and also 'Root
Partition'.