If anyone remembers my post about oil leaking from the starter, I wanted to update the final resolution to the problem.
It was in fact a cracked rear main seal. A $12.00 part was replaced and my oil leak is gone at last. I also wanted to point out that the tractor was listed by the original owner as a Yanmar YM195 when in fact it was a YM1500 all along.
The nice fellow that I bought the tractor from, separated the tractor, replaced the rear seal and buttoned it back up, then delivered the tractor to my driveway at his expense. He also rebuilt the steering box and I think he did some minor clutch work while he had the thing pulled apart. He could have told me, "Sorry, but it's buyer beware. I ain't using my time to rework a tractor I sold to you at a good price". But he repaired it at his time and expense and even removed the starter gasket and gave it to me in a box along with the defective part.
I also found a drawing that shows without a doubt that the starter has a gasket when new. There wasn't a drain hole on the bell housing so he threaded one for me and I am proud to say that no oil is entering the clutch housing and the tractor runs pretty darn good.
Finally some good news for me for a change.
Thanks to everyone here who helped me determine the issue[s} and gave me the right steps to take to remedy my problem.
Regards,
Torx