Speeter, M. E. (1955). U.S.P. 2,708,197, ChemicalAbstracts, 1956, 5035.

..it seems it's the patent for the synthesis of tryptamines and production of a range of various novel tryptamines, which i haven't had time to look at in detail... US2870162A - Production of certain tryptamines and compounds produced in the process          - Google Patents

(apologies time in my writing only allows me a quick stab at this issue...the theory on military wartime invention is a good one..i also would have imagined Manske coming up with it..hope you find the answer clouds!)