Well, looks like you were spot on!
called around, no one had #11 in stock so be a few days to a week, was at the farm cleaning grain so figured take a closer look, and yeah looked like most the oil was coming from the centre and not the edge… so pulled it apart… seal #14 was pretty old, rough and torn!
So built a new one, put it back together. Haven’t ran it much but so far no leak! I didn’t have to use any wire on the bolt though, mine had the small bendable plate to hold the bolts in place.
little trick for anyone making seals, if you want to make a hole in the middle just put the right size socket on it and give it a smack on an anvil, makes a nice hole easier then trying to cut one out