I have no idea if somebody has done it before, but that shouldn't stop you.
There are a few things in your favour on that costume: very limited boobage, and short pants under the skirt.
What I'd do is to build it with two or three commercial patterns. Go to a good fabric store and check their pattern catalogs looking for something with a similar shape to the shorts, the dress/skirt and the cape.
The biggest labour will be to sew all that gold trim, but when you get to that point most of the costume will be ready by then.
Glove making is tricky. See if you can find them done at a bridal store. You'd save some trouble that way.
Also, if your sewing skills are limited I'd hire someone or start with something simpler.
Best of luck...