Envinrude 1970 9.5 9022c - Replacing Water Pump -steps

I am replacing the water pump on a newly acquired 1970 9.5 9022c. (free)
The bottom gear case was already off, and the water pump was dismantled.
Need to know the steps required, I do not see any gasket between the base and the housing, should there be one or how is this sealed?
On the opening for the drive shaft in the housing(not the water inlet) I have a rubber washer with a brass ring that connects to the drive shaft tube going to the power head, is there a water seal in the opening of the housing ( I have the O-ring at the top of the shaft). As I see it now if there is not a water seal water would be able to go up the drive shaft tube...is this normal.

Thanks for your help
Steve

That seal around the driveshaft opening is important , it keeps exhaust from getting into the pump and also keeps exhaust from going up to the motor.

I see how this would stop exhuast from getting into this tube. but will water be in this tube? I don't see a seal on the shaft where it passes through the housing, as it is now water would be able to go up the tube.

There is no seal on the shaft where it goes thru the housing.--------This motor is 40 years old and I do not think it needs one now.

Ok, Why I was confused is in the parts diagram they show a seal and washer..

Would you know where I could reassembly instructions, I'm looking for the sealing of the hosuing to the base, and do I need to apply gasket/sealer to any parts before reassembly.
Also I read on another forum(I think/maybe this one) that the lower case has some type of sealant between it and the upper case?

I never use sealer when working on one of these pumps.-----------It is not the same as working on an automotive waterpump that only has so much coolant in the system.-----The outboard runs in an endless supply of cooling water and a wee leak does not matter.-------------Some will argue the fact.

I am replacing the impeller on a 1970 9.5 and the o ring on end of main shaft is in pretty bad shape. Does anyone know the size of the o ring at the top of shaft.?

The o ring is part # 303067.