Nice update. Looks like some D8 series batteries?
Was going to ask what the circle in the door was for....looks an armored truck gun port.
Scrolled down a bit further, Ah-Ha! Motorcycle handle bar clearance.
^^^ if you have/want Carling Contura style switches that's the way to go. You can buy the whole switch or just the rocker.
Dymo makes clear label tape if you want to try that, not quite as slick, but better than the old school embossed label makers.