@ Char1ie
If it was prop related, then it shouldn't have the vibrations in neutral.
I have also tried to drive the car to until the vibrations are there, and then push down the clutch and let the car roll ... then the vibrations are gone.

@STU
Sounds really good Stu! ... guess this is my next move then. If this doesn't help, then I might have to look at flywheel and clutch ... might be some sort of in-balance there.