big side mirror questions ? '65 c10

[Woogeroo]

so I bought these painted big honkin' side mirrors and now I have a few questions about them.

1. what are these size and type side mirrors called?

2. is there a gasket that goes between the mirror bracket and the side of the truck door.. like there are on the other type mirrors ?

3. if there is a gasket... I doubt they make one.. so is it possibel to buy rubber gasket material and make my own to fit?

Thanks,

-W