When you said lower legs were good shape, does that include the part the OD of the seal touches??
If they were changed before, by a butcher, they may be SCARRED where the seal presses in.., then when you pump em up and down they leak out there but it takes a while to see it..
As far as the forks not draining easy , do you mean with fork caps on ?? that causes a sort of airlock, not letting it run out..