^ Great advice.
However, as a note the OP - the "fantasy world" you've created is also important.
I've never seen steampunk that incorporates Victorian social reality to any great degree. It's a romanticises / idealised fantasy.
It's useful to know about - but I'm just saying, you have a lot of freedom with your costume. Some degree of historical accuracy can really improve your costume and make it more than, "lol, I put on a corset over some beige and brown clothing", but it's also STEAMPUNK - the Victorians definitely didn't have ray guns or airship pirates, either.
I misread that you were an airship mechanic - but if you're not, it doesn't really change that much. Though if you're in a "workshop" setting doing kind of "tinkering" - you might reasonably be much less dirty than if you're constantly running around below-deck.