This is actually something I've thought about a bit, as Osman Heavy Industries originally started as a company providing construction services, not a company building war machinery. One barrier, I think, for a lot of ideas (though weapons are by no means excluded from this) is that they run into the problem of "Who will use it?"
With things like guns and military hardware, though many such items go largely unused, there's at least an easily identifiable potential buyer (The parent faction's military). I think one thing we could be doing as to help promote a better diversity of products and services is to use and purchase each others's services and products more frequently, and to work together OOC to try to make sure that stuff doesn't just sit unused.