Oil Seal at Bottom of TO-20 Distributor

Is there a seal at the bottom of a TO-20 distributor to prevent oil leaks?  October 28, 2016.

I’ll double check the parts book, but I don’t believe there is. There is a brass bushing, and a screw in the side of the body which is removed to refill the bottom of the distributor with oil as described in the Factory Shop Manual.

What is interesting is these same distributor castings are used on GM cars and trucks, but have a grease cup in place of the screw slot plug to lubricate the distributor shaft with grease. The cup is supposed to be turned down periodically to force grease into the lower end of the casting, and refilled with grease when the cup is turned all the way down.