Hello Nicholas!
Thanks for expressing interest in our mod parts!
>> Do your explorer cases (39mm & 36mm) have screw down crowns and full gaskets/diving capabilities?
All our cases only has screw down crowns. It is actually described in the specs of each product page. On the note, we don't produce non-screw down cases.
There is no diving ratings for explorer cases. Even Rolex Explorers are only 10ATM and cant be used for diving.
If you bring it to diving, explorer cases sapphire crystal will either leak or pop out due to pressure. This applies for Rolex explorer too.
Since your life would be at risk if you go diving and your watch leaks or damage while you are in deep sea. Not worth the risk if you ask me. Best to get a true tested dive watch, such as g-shocks or rolex submariner.
Hope this helps. Let me know if you have any more questions.
Cheers,
Adriel