I don't have any drawings or pictures to help with, but would suggest asking over on the Doubleguns Journal forum first, and the ASSRA forum, second.
See if you can find the Frank DeHaas books, in the Mr Single Shot's series. Chances are really good that he has covered it, and if not, there are a pile of decent drawings of various set trigger mechanisms that may work, or at least provide ideas.
Check your local public library first! Some booksellers think they got the original copy of the bible, autographed by the big guy hisself, when they are listing the DeHaas books!
If the library system does not have any copies, hit up the nice lady (probably) or guy, at the information desk, and ask about interlibrary loans. Essentially, they put out a request, and other library systems send the books. Generally, you get them for a couple weeks to a month. Lot's of time to peruse the volume, and make a copy of useful info for academic purposes
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Cheers
Trev