Oil Tank breather

Yes...problem...like having an air leak in the manifold...the balance pipe is on the engine side of the carb. Unpredictable outcome.

I have converted my 850 to a single Mikuni carburettor and dispensed with the standard air cleaner. This means that the oil tank breather pipe has nowhere to go (NB not the breather pipe from the timing cover).  My plan is to run the oil tank breather to a catch can which has a vent to atmosphere on the top.  This should prevent oil spraying out.  I really don't like the idea of blowing oil out of the end of the tube no matter how far away from the wheels it is

I am carrying out a complete rebuild of my 1973 850 Interstate and about to replace the felt oil seal on the rear opening where the drive comes in from the gearbox.  Having previously had Commandos I know that this is often the source of oil leaks.  Has anyone tried putting a suitably sized oil seal in, sandwiched between the mild steel plates then spot welding it in place?  If so did it work and do you know which oil seal you used?  I am curious as to whether this would be a better option than the pretty useless felt seal before I waste a new set of retainer plates and seal.

.. I too had a single carb and just fed the oil tank breather to near the back number plate. I never had the slightest trace of oil coming from it.