Hi Jonathon,
Re water for your radiator, just put 2 or 3 clean plastic buckets out in the rain and store the water in a clean container. I use the water from my rain gauge (a necessary device in dry South Australia if trying to grow things).
Regarding the cork gaskets under the water dome, there are different thicknesses available. Mine were weeping which can be caused by too much coolant in the water as it is very searching. When I changed mine I smeared both sides and the edges of the gaskets with silicon sealant and had no trouble since.
Regards,
Bob Mather.
