Rick,
Kindred spirit here, brother. I'm in the same boat; I'm building a Snape costume for Halloween and next year's
Deathly Hallows premiere. After hours and hours of web crawling, I haven't found much to help, either. I am now building a "Snape reference archive" of hi-rez photos, internet references, a collection of DVD screensnaps of each movie, base patterns for the robes, jacket, pants, shirt, etc., to help in my construction. I, too, have seen Yvette's site, and Lisa's (severelyrightbrained), MadameMalkin's (spammed) site, and the Twin Roses site…most of the fansites I have found are useless for research purposes. I check in here on the RPF occasionally, but don’t post much (I usually lurk and learn); I’m glad I decided to drop in! When you can, check LiveJournal for Snape costumers, and Cosplay.com has quite a few, also.
As for patterns, I’ve decided to use McCall’s Civil War men’s jacket A (M4745) instead of the Butterick cassock; it has the waist seam that Snape’s jacket has, and is fitted similar. I plan on making the collar higher and flare it, adding the appropriate flat, fabric-covered buttons, narrow, flare and button the sleeves, lengthen and spit the tails/skirt, and add the patch pocket flaps. I’ll be using a deep dark blue wool suiting, as his academic robes appear to be black, and the wool jacket is a really dark blue. The robes are an animal unto themselves; I’m culling through my ancient SCA archive for something I can modify. I haven’t found a good pants pattern yet; I am looking for a vintage high-waist, flat-front style, that I can flare the cuffs and add the buttons to. The white shirt will be a Victorian with stand collar, with a simple black silk scarf/cravat. The boots….it’s been a challenge so far to find a flat, pointed toe men’s style…I’m still on the prowl, but may use a modified cowboy boot.
I’m trying to drop a few pounds before I finish the coat (the pattern runs tight at the top fit), but I’m not too concerned if I don't, as Snape has a slight paunch himself….I’m 6 foot tall, so it should balance out. I’m debating on whether to use a larger nose appliance…mine’s pretty big as is, but shaped more like Dumbledore’s!
Anyway, if you need something, let me know or drop me an email…I’ll be monitoring the RPF for replies and updates.
Rob