Checked the oil a while ago and its was low and wet. Changed it for new stuff now I have nice new oil dripping

I gave it a good clean down to see where the oil is coming from and it appears to be coming from the top of the case. I think its only leaking when in use and then dribbles down. It may be coming from the output seals and getting 'blowen' to the top.
Where are these things prone to leaking? Is it likely to just be the seals? Is it possibly out the top? Breather?
What experience have others had with these and ways to work on it?