Water pump seal 1930 Dodge

I am overhauling the water pump in my 1930 Dodge DC-8. I have made a new shaft from silver steel and new bushes - outer is bronze, the inner is "oilite". Lubrication is by oil at both bushes. I am overhauling it because water was coming out of the rear bush oiler.

There is a gland packing in front of the inner bush. What should be on the inside, between the impeller and the housing (which is flush with the inner end of the bush)?

I believe it is called a "packless" seal and have seen references to carbon. I have also seen this diagram

at http://airconditioningmanuals.tpub.com/TM-750-254/TM-750-2540026.htm showing a seal of some kind with a spring between it and the impeller.

I have answered my own question I think. Here is a diagram of a 1935 Studebaker Dictator water pump. If you disregard the bypass it is a very similar design to the Dodge. So it looks like there was no "seal" as such, just a thrust washer and small clearances. The "oilite" bush would prevent water coming out of the oil cup.