I've had exactly the same problem.
Replaced the quick release fuel line with a brass fitting and re o-ringed the wiring line.
The removal of the electrical line is indeed a nightmare.
Getting the circlip out was very difficult, then had to punch out the electrical plug line.
Used a 3mm (1/8") pin punch. ( gently too, having said that it was very tight) Best held in a vice with soft jaws.
It was a bigger nightmare fitting it back in, shredded one of the new o-rings, got it on the second attempt after fitting another o-ring, i threw viton o-rings in ( m10 x 2mm, times 2)
Liberally apply lube to aid fitting, you wont get it in otherwise & take your time.
Appears to have worked so far but actually firing it up and riding it may yield a different result.
Thanks for the pic of the plug.....removing the pins was tricky and i didn't write down the sequence for the plug.
That's all i've got on the subject.