I'm thinking that's a grease point. Please take ANYBODY's advice over mine here, but I think that's a greased motor, not oiled, and I "think......" if I'm even right about the motor being the same, which I might not be... But I kinda think it is...) it had both a "grease in" plug and a "grease out" plug at one end, and only a "grease in" plug on the other end. And I'm pretty sure that the one we used to have (which I'm only "pretty sure" is even the same...) had no actual grease fitting. Either they had a proprietary one, or it's a standard fitting size that's not in my collection.
Take that plug/bolt out of the end of it and see what's in there....