The nose guns, at least I assume that's what they are, were halves
from aircraft external fuel tanks, thankfully I had 4 that matched.
The muzzles were kinda right shaped bits
I found in some Japanese robot thingy kit.

The missile tubes were a single item turned up out of
resin after drilling out the holes,
saved trying to do it after the cone shaping I can tell ya.
Just moulded and cast 2 off, that was that job dealt with.