Camper Mirror location reference - and gasket/sealer question (for mirrors)

[jocko]

Transferring camper mirror mount locations from an original door to my 'new' driver's side door. Thought I'd share the measurements I took for ref if you need them. Note, I would NOT drill all the holes before mounting - I plan to drill the upper forward mount hole, then place a level on the bracket and drill the remaining two - using the reference marks just to QA the process. I'll also put an erasable mark (probably on blue painter's tape) for the lowers and see how they line up before drilling. Anyway, this is where they go. Note the upper hole vertical reference is from the upper straight body line of the door - hopefully apparent in the pictures.

Btw, does anyone know if any gasket or sealer material was placed between the mirror mount and the door itself? My truck had some funky goop that I doubt was factory, so just wanted to ask. Thanks.