Aaargh, it would be the radio! OK, that's not good, but it's sometimes recoverable with a different RUU.
Problem is, RUUs are ROM
Upgrade Utilities, so won't let you downgrade, and it has upgraded your HBOOT. So it may well be that no other RUU will run.
What I can suggest is downloading a new copy of the 2.3 upgrade from
shipped-ROMs.com. These provide md5 codes, which you can use to check whether the download is good before running the RUU. The 2.3 upgrade is near the bottom of the list, in a zip (together with some other stuff).
Otherwise the most recent TMP-UK RUU I can see there is
Shipped ROMs. Unless you have a "goldcard" you will only be able to run T-Mobile RUUs or the 2.3 upgrade - the phone was originally T-Mobile and the RUU will check.
I'd try a fresh copy of the 2.3 upgrade first, then if that doesn't work we'll just have to see whether the T-Mobile one will run with the phone in this state despite the 1.02 hboot.
Before trying, do remove the battery for a few minutes, make sure everything is discharged and cool.
Good luck.