I quite agree with all of that Hogo. The design of our oil system dictates that there will always be some seeping back, its just a matter of time / quantity. I dont loose any sleep over the matter, and would not reccomend spending huge sums of money trying to rectify modest amounts of leak back. If, as you say, it becomes tedious draining off the excess, the fitting of an anti-sumping valve is usually the complete answer. None of our own Vincents have the need for such a valve, but I have fitted a conway item to a square four, and one of our own manufacture to Petes triton. Both of these are completely successful and have caused no other lubrication concerns. I hope all of this helps Pete 4000 come to terms with something that is probably not a serious issue, but as I have said before, a wise man will keep an eye on the situation to ensure it does not become a problem.
John