H.F. Wichmann copyrighted the "Aloha" spoon. ::::: Wall & Dougherty copyrighted the "Honolulu" spoon of which Watson was a subsidiary. :::
All this has already been established, I'm confused why you go over this again. :::
Old books won't solve this mystery, but retrieving the copyright information and documenting new spoons such as the "Aloha" spoon will help to solve the mystery.
The H.F. Wichmann copyright record is pre-1910 and must be considered the original source of this spoon design. :::