8HP Briggs Governor Shaft Leak

[Lawnmower collector]

Neighbor brought me a DR walk behind brush mower to fix. Drivebelt was soaked with oil and slipping, oil appears to be coming from the governor shaft, leaking just sitting not running. I ordered a new seal and took the governor arm off but there's no seal visible from the outside. Just a bronze or brass bushing that's pressed into the crankcase. I haven't replaced one before, is the seal installed from the inside or does it even use one? The governor shaft isn't real tight fitting to the bronze bushing. Engine Model 195707 Spec 0468-E1 Thanks

 

[ILENGINE]

Parts diagram suggest that one was used. Some engined didn't come from the factory with it installed. There should be a recessed area behind the governor arm for the seal to go into from the outside.