O.K. I had a failure to write cdt.bin, logo.bin and ebr even though they were right there in the directory with all the other files.
This resulted in a general failure.
I got stuck on the dual core screen, pulled the battery and rebooted into recovery, sideloaded .902, side loaded.905. Both loaded fine.
Tried to load the .230 file and got a signature failure - abort.
So I rebooted and now seem to be on 230. I have no idea whether or not it worked, but handset resports that it did.