The tail shaft is of excellent build quality, I can't imagine it ever having a reliability issue. The previous owner of the car had big HP plans for the car which never came about, being the reason for this tail shaft and the ridiculous clutch that I'm also about to take out of it.
There is nothing wrong with these parts I'm removing, just that they are too much for the car as I want it.
As for vibrations, at first I thought this tail shaft was the cause of a vibration the car has but since changing the diff and tail shaft back to stock items, the vibration is still there. So, I can't fault either of those items for causing a vibration as it's still there. I'm now thinking it might be in the rear wheels or something else like that.
I will get some proper measurements tonight but from memory length is a bit shy of 1400mm overall, width would be a bit shy of 90mm and weight would be about 8kg at a guess just from carrying it on the weekend.