Yeah, they cost a lot more outside the USA, and then there's postage or a premium price to get one from a shop.
I've found another one, but it's up in the attic, still in a computer case, and may also be kaput, even if I can get it down. (It went up so must be able to come down! I just need to remove some of what went up there after it did! lol)
Tbh, the transformer, if I can get it sorted, is much neater.
I've managed to find some basic info on transformers, and with that and deciphering the writing on the component, it becomes obvious that it wasn't any sort of rectifier. It was some sort of protection for the transformer itself, originally cutting the supply if the primary got too warm. I can't find a replacement, though, so, yes, I will just have to be careful not to draw too much current.
The diagram is very helpful thanks, especially for the use of capacitors.
I'm still struggling to figure out what rating diodes/rectifier I need. I have two bridge rectifiers, but no idea how to tell what rating they are apart from the 'forward voltage' , but I don't know how that relates to current etc. :S
I'll have to go back to the shop because, surprise, surprise, none of the dozens of capacitors I have is anything like 2500uF 25V or even 2500uF 16V. I seem to have lost all the ceramic capacitors too.
Hopefully there will be a more knowledgeably chap on the counter this time!