Have found the source and part no. for the metal version of the fuel tank coupling which appears to snap off occasionally (workshop thread by Dobro-dog started me looking). OEM part is plastic and snaps off at the neck leaving threaded section in tank plate. (This has happened to me.)
For the UK the supplier is Tom Parker Ltd (01256 330033). The part no is: LCD100040V. They cost £12.00 + vat. Sure am glad to have these even if I did have to pay ridiculous courier charge.
If you snap them off while trying to remove them (as I did - much swearing followed), get yourself a soldering iron with a cutting tip (flat tip) and work it out that way. Everything else I tried moved me closer and closer to mangling the steel plate.
Remarkably poor design. The metal females work so much better. Just be sure not to overtighten them. I got mine from Team Triumph here in the States for $37.00 USD (females only). These mated up to the metal males supplied by Triumph nicely.