Saving Old Seagulls

As per picture, I would tap the top part of the pin straight and pull it out from the bottom, Make some new ones from brass bar, with some extras.

Completed a strip, clean and inspection of the lower unit now, happily the pinion, bevel and bushes look like new!

The old grease had a "marmite" like colour and consistency. The still present sticker on the cowl states Castrolease underwater grease for the gearbox.

As much reading as I've done, I cannot find a relevant modern alternative to this. I do have some Castrol blue marine grease but it's very thick in consistency, and not sure if it will rob too much power if I pack the box full of this.

Keith, is there any mention of quantity in the manual you have please? I didn't receive an email from you with it attached.

Sorry about that, I thought I had.

No worries Keith.

Am I correct in thinking the exhaust runs in a tube adjacent to the drive shaft? Which then exits directly into the impeller housing? I'm trying to get my head round the flow of water from that too, the two small holes at the rear of the leg must be the inlet and exhaust?

I'd have a feel where the exhaust gases are coming from but I'm not that brave to feel down near the prop when it's running!

Am I correct in thinking the exhaust runs in a tube adjacent to the drive shaft?

Yes.
Half way down the leg are three screw/bolts, inside is the impeller, it just keeps the exhaust and cool.

Mine is at the very bottom, above the gearbox. From this very rough schematic I've thrown together, is this correct that the exhaust gases flow into the impeller housing, then out via the two small holes on the opposite side of the prop on the gearbox? I can't see a way that they would come out of the "duck's beak" hole on the lower leg like I would have thought.

One question, has your drive bar a key way around half way up of it?
That will answer your question.

I don't know as I didn't split the lower leg section. Just opened the box to clean and re grease.

As far as I can remember, it pumps water into the exhaust/drive tube and it comes out with the exhaust gases.