For what it's worth, I had a DS2072A with 00.03.00 SP1 H/W version 2.0 which refused to downgrade its OS, and therefore wouldn't work with the DS2072AUpgrader, but I was able to upgrade following the steps from JSE009's post (page 3 of this thread).
One note, I found that RigolBildschirmkopie application was quite buggy both on Windows and OSX, so although it eventually worked to dump the memory, it crashed every time I tried to paste the key SCPI command window. I assume that this is the same reason that JSE009 used UltraSigma to upload the new keys.
After this, my scope now shows all of the options unlocked, the bandwidth set to 300MHz and the model number now shows DS2302A.
Thanks to everyone who put such a lot of effort into getting all this to work.