I agree about the threat of dust being more to do with the fabrication. I always use a face mask when cutting MDF.

Maybe a compromise for the chassis would be just to allow the electronics to be protected in a metal enclosure(s) affixed to a plastic or timber base plate. A softwood chassis could then be formed around the base plate to affix armour and provide a anchor for weapons. This would avoid the need to seek out hard woods which even in small amounts are costly nowadays.

Hoppy