I suppose this post will also serve as a belated "intro" post, so greetings! I'm a life-long gamer (with tendencies towards strategy, role-playing, and tactical games) who recently moved from working in a college library to working in a high school library at a small private school in Baltimore.
I apologize for how long this request is, but the help I need is somewhat specific in nature...
As a way of "saying hello" to all of the new kids I'm serving, as well as being a fun, Halloween-themed library event, I've decided to combine my love of H.P. Lovecraft with a little bit of ST/GM/DM-ing to create a sort of LARP that the students don't even know they're participating in.
I've created a telegram (PDF template provided courtesy of the H.P. Lovecraft Historical Society) to the principal of the school in 1927 that I "discovered" in one of our older, larger tomes that never gets touched (aging the paper with liberal application of tea and toaster-oven seems to have convinced just about everyone it's real). It contains suitably cryptic references to caverns under the property (the grounds for the school's current location were purchased in 1925), a lack of information on eighteenth-century land ownership, and man with a generic name about whom nothing could be learned beyond his existence. Hidden safely behind clear plastic, I've been drawing attention to it from all of the students passing by, and it's met very little skepticism.
I've also done some digging in the school archive to make copies of yearbook and school catalogue pages from the same year - a few of whch I've put on display, and a few of which I've reserved for later modification to imply someone doing research on the subject in the 1990s gradually uncovered a horrific plot to unearth an eldritch horror sucked straight from the mind of Lovecraft beneath the same neighborhood in which the school was to be situated (construction wasn't finished until 1928). The then-principal also learned of this plot, and managed to foil it, but was driven mad during the act, which explains why he left his position that same year due to "declining health."
Unfortunately, I've reached an impasse in my gradual uncovering of these "genuine documents."
On the idea front, I don't know how I can effectively bridge the gap from authentic (and "authentic") documents from the 1920s and late nineteenth century to these researcher notes without the logic leap being so huge as to make it obvious the whole thing is staged. I expect them to figure it out eventually, but much like The Game, I've essentially lost as soon as they realize they're playing (although if it helps inspire some kids to do research on the school's history on their own time, I'll consider it a tactical victory).
On the resource front, I'm afraid I'm shy of authentic (or authentic-looking) documents from the 1860s, 1890s, and 1920s, all of which are pretty important to pulling this off to best effect. My image-editing skills are - alas - sub-par, and my hand-drawn artisitic ability is a few degres worse. I've already exhausted the free props of use from both the HPLHS and Propnomicon, but I'll almost certainly need more before my event/display concludes on the 31st. Unfortunately, I was unable to secure any library funds for the project, and most of the physical objects I was able to find online are either (expensively) custom-made or at least more than I can afford to put into it personally.
If anybody has any ideas or documents for the specifics, or perhaps more generally has experience with Call of Cthulhu LARPing in a library setting, the assistance would be greatly appreciated!