tank for air cooled 3.5hp

[richard green]

I have a quite elderly 3.5hp air-cooled engine which I bought on e-bay last autumn, so it got no use before winter. It spent the winter tied upright to the mast support in my sailing cruiser which in turn spent the winter afloat on her tidal mooring. After a bit of a struggle, I got the engine running sweetly at the weekend only to discover almost immediately that there is a serious fuel leak in way of the mountings for the recoil starter. I'm currently getting it brazed/soldered, but am wondering wether or not to get a new/secondhand tank or not. What would probably be ideal, given the age of the engine, is to get a non-runner that I could canibalise for spares?
Any offers will be gratefully considered....