Thanks for that.

I managed to get the 64 bit version 0.9.2.3 wallet from the dropbox link in the OP, but the updating with that was no better than the 32 bit version. I have already gone so far as to write a small routine that opens the wallet, lets it run for two minutes, closes it cleanly, waits for 10 seconds and then restarts the wallet. This has got the wallet updating in fits and starts but it might be finished before the day is out at least.

I will give the new wallet a go ...