The best bit is that none of the script actually calls any objects directly (no dependencies), so I could in theory have an unlimited set of buttons that generate any combination of ship and weapon from the pool of available parts. All I need to do is type the ship / weapons name into a message sensor.
Mmmm, i don't quite understand this bit, by 'none script is calling any objects directly' you mean every object created by this script is checking itself if its ID is selected in 'creation' script?