http://www.forgottenbooks.org/ republishes old books and offers free full-text free versions online through Google books. There are several occult and magick -related works from the late 1800's and early 1900's that might be of interest as inspiration for pseudo-magic symbols, esoteric quotes, incantations, and other stuff for steam/occult stories, props or LARPs.
After a quick scan through the titles here's a few I saw that might be worth looking at, and there are few more I think I missed
Ancient and Modern Initiation
The Book of Ceremonial Magic
The Book of the Sacred Magic of Abramelin the Mage
The Coming of the Fairies
Demonology, by King James I
The Fairy-Faith in Celtic Countries
The Gardnerian Book of Shadows
Letters on Demonology and Witchcraft
The Synthesis of Science, Religion, and Philosophy Vol 1 & 2
The Vampire, his Kith and Kin