I have been successfully able to upgrade my 106j from DSM2.3-1141 to 1157,
with Goetz trick to let the unit believe it's a 107.
But the interesting thing is that as I read that it was not (any longer?) possible to downgrade to the old DSM2.2
I first went from DSM2.3-1141 down to DSM2.2-959, by changing the /etc.default/VERSION file! And it worked!
In my case I copied the content of the /etc/VERSION to /etc.default/VERSION, because the /etc/VERSION
contain a very old number, probably the first FW the NAS has seen, and that file has no longer updated:
Synold> cat /etc/VERSION
Once I verified that the firmware was down to 959,
I went for the regular upgrade, and now my old NAS is up to level 1157