I personally don't take things as far as that chap's urania. It looks to be a very neat job but in my opinion is perhaps a little over done. As far as I know, the gold is not original (at least, it isn't on my own example). Personally, I don't bother polishing the outside of the boiler though I do try and replace all valve knobs.
Don't get too hung up on the details. Once your boiler is descaled and the groups have new springs and seals it will be making shots as good as ever.







