The new Fall pattern lines don't have an abundance of steampunk possibilities, but there are a few.
McCall 6800 - This is a really nice coat that could work well with a steampunk costume. Or which would just be a nice, feminine everyday coat.
M6799 - This is a nice, full, long skirt that would work if you need a quick and cheap pattern for a long skirt.
M6818 - This (and the costume below) are apparently Once Upon A Time styled costumes. I haven't watched that show yet, so I have no idea about its costuming. But I think they both have steampunk possibilities if you leave off the more fantasy elements.
M6819 - If the Renaissance elements were left out, this could be steampunked, probably.
M6815 - This is a cute Wizard of Oz costume that maybe could be made more generic for a boy's steampunk costume.
B5935 - Butterick has a new "historical" corset pattern out. It's really a modern take on a Renaissance style, I guess. It's not unattractive, but it's not historically accurate, but if this is a shape you want, this may be a good start.
B5936 - Gauntlet, Water Bottle Carrier, and Pouches
This is interesting. Brass details could steam these up. I'm especially intrigued by the one with the three bottles, but it's hard to tell exactly what any of this is. I'd like to look at the patterns.