Just a heads up, if anyone is interested.
I still have the transformer that I removed from my 2003 Triton when I upgraded my electrics (see here).
If anyone needs a replacement transformer then they can have it with my compliments provided they are prepared either to collect it from Christchurch, Dorset or to pay the carriage.
If possible, I'd rather it went to someone who is currently experiencing transformer problems rather than as a 'just in case' spare that might never be used.
The transformer was working perfectly when it was removed from my BIP as the problems that I experienced were due to defective components on the printed circuit board.
Send me a PM if you are interested.