Mil spec pots

Do you mean to refer to multi-turn wire wound precision pots?

Because there is no mil spec any more. They and their contractors all use COTS now. There are high reliability component makers, which they can choose or be contracted to specifically incorporate into a product.

The solution to your needs could be any of several families of applicable discreet devices.

One would need to see more requirements analysis data to help you.

These will be used as one leg of a whetstone bridge for a thermostat but they are living in a damp building (out building in Florida)

Bourns' multiturn wirewound pots are pretty well sealed up. They may even have sealed versions.

Thanks I have a couple coming