This is For You !
When I wire cars I do this . As you know wiring in cars is many sizes that you can see .What I do is get regular house and electronic wires , ( they're building a lot of new houses by me ) and neighbors give me defunct elecronics for salvage .
This way I have about twelve different sizes of wire at any one time . No , don't ask the guages . Suffice it to say it ranges from 1/25 radiator hose size to 1/25 single wires for under hood work . In the case of engine wiring I do this . Take the tiniest wire you have and remove about an inch of insulation . This ,cut in equal bits makes the boots on the plugs .
Now you can run your wire from the next size up , Be careful and you'll be rewarded with a kick - butt wiring job . T.B. P.S. You see , different sized ship models , require external detail that cannot be done in plastic . So I use wire !