Woooooooaaahhh !!! My precious 
All good so you get allmost all !?!
Yes for your elec enclosure you can print it, but it work really fine to make your’s hand made in époxy/fiberglass !
He got a good tutorial that we all follow : HERE and some more here 
- OKP is a magician and has incredible skill and patience.
:lol: That is true, OKP MASTER still win !!
If I read weel your step is good,
2 - resin and hardener mix and one layer of fiberglass/carbone exactly (you can insert your fixing hole between 2 layers of fibreglass/carbone but put fiberglass inside to separe carbone from electronic)
3 - you could make step 2 in 2 times, 1th the part and then see how all fit, you can adjuste them cut you fibreglass enclosure to adjust and then reput fiberglass and carbone to re-enforce all !
- And then sand down, paint and you can reput a fine layer of epoxy to protect your paint/graphism 2
You can easly do it, I saw that you knew very well tinker ! This is a new experience and can be usefull for your drone or everything esle if you want to add a light body of carbone on it … And your enclosure gonna have the same concave of your deck ! And the mini space under your deck
Its a good deal I think.
otherwise I have « VENDS boitiers batterie Alien ABS et fibre diy (#1) »
good continuation