First of all, yes, I realize this is not technically a steampunk Dr. Frankenstein costume, but a steampunk Dr. Frankenstein's Creature costume. But I didn't name it, the people who created The Nightmare Collection of Halloween masks and props did. And if you saw some of their other no-more-nice-dreams-for-you pieces (check out the Related Products links above), I doubt you'd be any more likely to argue with them about the name than I am.
Second of all, I've gotta say hats (scalps?) off to the merger of history's greatest haphazard biological tapestry with pop culture's favorite hybrid technological one. It's industrial-era beast meets post-apocalyptic nod to the industrial era. And it's pretty creepy. Especially with the dude modeling the costume posing like Hamlet giving his monologue to that dead guy's skull, even though he himself looks more like the dead guy. Hey, there's a Halloween costume idea for Shakespeare
nerds enthusiasts: dress up like a sinister, skeletal Yorick the Court Jester and walk around talking to a freshly beheaded Prince Hamlet prop all night.
The Steampunk "Frankenstein" costume includes the pictured mask and arm piece, both designed by master sculptor Mario Chiodo, and painted by hand. One size of fits most, with the mask measuring approximately 32" long x 18" wide x 27" high, and the arm 34" long x 17" wide x 4" high.