Well, the metre long tube high up behind rear bumper with the original ball valve breather removed (and a plug with a 1mm hole in it's place) idea hasn't cured the leak either.
The shiny stains creeping all along the outside of the bumper are getting embarrassing, looks like the local tom cats have been busy on it.
Really amazed by how much oil this thing can push out, and how far.
Have ordered an alloy fuel filter housing to try in- line on the pipe, maybe the wide spot will drop the speed and pressure enough to allow the oil to collect there .
Beyond that, I'm planning trying to use the side mounted oil filler as the breather to see if a different location can cure it.
It's a big bugger though, M16. Available, bolts seem to be 8.8 tensile or above and tricky to drill a clean hole through, nylon ones are available but usually the wrong threat pitch.
Oh well fingers crossed that the physics are in my favour and the bottle works, must go and wash my bumper