Flyboy

Nice pictures.

For reference, the standard propane regulator is 37 Mb. 1Mb. = 0.401865 inches of water, so 37Mb. = 14.87 inches on the water manometer.

I don't see an expansion vessel in the op's pictures, I doubt that he has one.

It looks to me like the green pipe is from the pressure relief valve. The valve blows off when the water expands on heating up. If you can get to it, turn the knob on it to clear any scale that might be stopping it seating.

2mm is way too thin.

All they needed was a Landrover !!

The OP said the LCD odometer had stopped working, I assume he meant the hours meter. This is a very common problem with these displays due to the ribbon cable connection to the glass LCD substrate ( worse during damp conditions ). Can usually be fixed by application of heat from an electric flat iron after stripping it out of the rev counter. Totally separate fault to the dodgy alternator.

Standard pump out fitting looks like this, https://www.midlandchandlers.co.uk/products/pump-out-socket-brass-ad-001-m

These made be able to help :- https://boulters-chandlery.co.uk/Engine-Room/Parts-By-Engine-Make-Model/BMC-Leyland https://www.lancingmarine.com/

I think the maggots are the ones holding the fishing rods.

You can get all the Talking Pictures on catch up here. https://youriplayer.co.uk/talking-pictures/ or here. https://archive.org/details/ScotlandYard12CompleteEpisodes https://archive.org/details/ScotlandYard12CompleteEpisodes/ScotlandYardTheGrandJunctionCaseEdited.mp4