Latest news on the fuel tank:
Despite my best efforts, and expense, the resurrection of my old tank has failed! I have cleaned and painted the outside and sealed the interior (which was remarkable rust free considering its age).
But, the reason I did all this - the non-functioning fuel sender unit has proven to be the worst problem. It stopped working because the rust on the locking ring became too advanced and there was a loss of electrical integrity! Still, Nil Desperandum I thought. I confirmed the sender was still working and attempted to replace it. However, the rusty locking ring started to disintegrate on reassembly and would not seal properly. I tried to help it out with some self-tapping screws to hold it in place, but, it leaks like the proverbial.
So, after two weeks of effort and wasted money I give up - the tank is headed for the scrap yard. I am going to have a bespoke aluminium tank made ASAP (because replacement Metro tanks are non-existent as far as I can see). I will continue to use Ethanol free unleaded (BP Ultimate) so I am hoping that any incompatibility between aluminium and ethanol will be minimised.
This is what I intended to do right at the start but was persuaded to try and refurb the original....I wish I had followed my original plan now
Attached is a photo of the sender unit in place for interest.