Thank you all!

Here's what I intend to do:


- coat everything internally,
but without a space-filler


- seals

* fixed, for plugs and tieposts: a locally made silicone based strong
adhesive/sealant + external soft silicone coat

* reopenable, for the box lid: just soft silicone sealant

* wire tieposts & coax plug:
- soft silicone sealant, left to dry completely
- then wrapped in aluminum foil (no metal contact)
- then wrapped in friction tape, held in place by telephone twisted
pair;
it's another suspenders-and-belt trick I have used this to
weatherproof all sorts of antenna contacts, some lasting well over 10
years


This for keeping water out,
But, in case it does somehow get in, what about WEEP HOLES?