Welcome along Mr M60
First of all, once you immerse yourself in this hobby as we do, you will begin to see things in the world around you like a scene out of 'The Matrix' when Neo becomes aware of the matrix & begins to see things not for as they appear, but for as they really are......................
In our scale, that means any object or item that you can see is automatically subject to analysis for what it can be used for on a tank or other AFV !
I used a fill for ballet Tutu's as scale netting for German helmets for example !!
For your aircleaner, a Donaldson with a a standard swirl intake cap, I would get dimensions of the real thing, and divide that by 16 to get you scale size requirement.
Once you have that, then every cylindrical object of any origin is fair game !
For the plate armour, ideally styrene sheet is the go, but if you dont have access to that, any firm plastic will do, or even copper or brass shim material could work.
This hobby turns a man into a keen recycle'r I can tell ya !
Your missus will soon notice piles of stuff hoarded to the side which would otherwise be in the rubbish bin.
Im looking forward to you gun truck build mate
