Volvo greetings to all from SA,

So the tedious task of replacing the rear engine oil seal was finally done this weekend. A new oil seal was purchased from IPD and fitted nicely.
There still seems to be a slight oil tricle now and again and i think that it could be the slight groove on the rear flange of the crankshaft.
Can this be the problem and can the crankshaft be re-built? Opinions please? The sump (oil pan) gasket was renewed a few weeks back.

I've noticed a few annoying oil leaks other than from the rear oil seal; oil seeps out from the base of the distributor and from the dipstick.
Does oil leaks have anything to do with 'crankcase ventilation'?
Can anyone explain this concept to me?

I know that if an engine is worn i.e. worn bores, the crankcase pressure can increase hence oil will leak from all sorts of places in the engine.
I am not sure if any of my attempts to seal the engine oil leaks will bear fruit because this motor may be worn to cause a higher crankcase pressure.

Lastly, is there any secret in obtaining a 'bone dry' motor after a long haul on a vintage volvo? I have never been able to 'keep the oil inside of the engine' with a vintage volvo.
Can anyone help?

Thanks,

Volvo for life - SA 122s