RE: Ultimate 120 cowling
The canopy is fiberglass.
Securing the canopy is up to the builder/pilot.
I don't use Wood screws alone as this is prone to crack the canopy.
A better solution is to use grommets with brass tubing to form an anti-vibration mount, then drill holes in the wood, harden them with CA and affix with longer screws that are harder to loose.
You can also install pegs from the back and secure the canopy with a removable clip.
This requires that you bend the canopy out slightly as you install it, but it makes it almost impossible to lose.
Even if the clip falls off the canopy is held in place by the pins/pegs.
Consider fabricating your own from plastic soda bottles.
The NP 120 is currently out of production.
Nitro typically pulls parts from new planes to service problems with orders.
If they end up with a few extra ARF's doing this, they will sometimes parcel out the components as parts.
Otherwise the Asian manufacturers tend NOT to provide spare parts as they do not have the merchandising chain to support parts distribution.