Thayer, which seal is leaking on the ebay compressor?
Afaik, there is a seal on the main shaft, a seal on the cover, and problably 2 seals on the casing, in order from small to large, diameter wise. How about the current compressor from the parts house? What has failed in it and does it have the oil hole at 12 o'clock?. Good you dug up this obscure but important piece of info with regards to the oil hole mark on the R4.