I'd been able to find Sherlock Holmes Costumes for men, women, children, pets and even a little Sherlock pacifier for babies! What eluded me was finding the Dr. Watson costume. It was there but I'd missed it.
Sherlock Holmes Regency Collection Men's Costume (above)
Now I have a Dr. Watson costume on my page. It is on Clearance Sale! Not available in many sizes but it will give you some ideas.
Also a lot of the cool Steampunk Costumes out now would work really well for Dr. Watson.
Take a look if you'd like to be Holmes and Watson this year.
Maybe this Halloween, Sherlock could also be accompanied by his long-lost cousin, Mike Holmes, of HGTV's Holmes on Homes? Choose your favorite coveralls and toolbelt, a hardhat or better yet, a real safe Cowboy hard hat.