I went to look at that bike last week and I think you got a good one. Very clean looking, and all there, good tires, and no sign of rust on the tank. Did he find the key?.
When I saw it there was an oil drip under the starter and it looked to me like it was coming out where the starter mounts into the left side case. Although it sounds like the starter worked for you, between the observations of oil drips an the way the PO described his starting problems, I'd say work on the starter while you have the oil drained.
I guess I should do the same, as I have the side cover off to do the starter clutch bolts.