Streamhound, I think I may have seen such a guide, but for me memory is a fickle mistress so I may be remembering coverage of the Park in the WPA guide to N. C.
I have seen a brochure which Horace Kephart and George Masa, in tandem with Bryson City druggist and entrepreneur Doc Kelly Bennett, put together to provide guided trips in and around the Park. It was in a large collection of Kephart material I recently sold to the University of Tennessee. What it reveals is that Kephart and Masa, while progenitors of the Park, also viewed it as a commercial vehicle. Not many know that.