Need replacement aluminum propane tanks F33

MY F33 has a narrow helm seat which is a locker with two tall, thin aluminum propane tanks in it. They are corroding a bit on the bases as some rain gets in the seat top. I am going to try to get house-door gasket locally to deal with this.

What I am most concerned about it the slight leak at the valve-top on the tanks. Teflon tape has reduced the leak, but not entirely. They are in the stern with the big scuppers below so I will not blow myself up.

I am in Guatemala so it is not easy to get new valve-tops, if at all.

Does anyone have one or two leak-proof tanks, of this tall type, that I can buy; have shipped home to Canada and then to my boat in Guatemala?

Failing that I will have to put standard tanks on the exterior of the stern, not a thing I am keen on.

Thanks, Ann