I recently had this job done by a local independent motorcycle mechanic. He is generously taking on some of the work on my Morgan, never having worked on one before, Since he also spends a bit of time on a pit team for some racing group out of Detroit, he is quite proficient. He recently replaced my original fuel pump at 5400 miles. When he purchased it he was able to source the entire kit except for the BMW seal part number from a supplier. In the kit he got for the job that convoluted tube was already fit to the fuel pump.
On a side note, I cannot believe how much difference this made to the throttle response and overall engine performance. It’s subtle but there is a big difference when I accelerate, and after starting the engine has not thrown a ECU warning at all. It had gotten so bad I left a USB cord attached and coiled up in the interior to delete the warnings after my rides.
I’ll try to get the specific part numbers and supplier for the Alternative Parts List for all the USA owners. The entire job cost me about what the parts with tariffs :-( would have been from the UK or Europe. About $550 total. :-)