Based on the patent date I see stenciled on the edge of the frame ("JAN. 3 '05") I checked the Annual Report for 1905 on the Smithsonian archive. There were several hand trucks and carts patented in 1905, none on January 3rd, though. There was a hand truck brake patented on January 3rd, but it doesn't look like it applies, the patentees are in Puyallup, Wash., and it's not assigned. There are no patents assigned to Eureka Truck & Specialty and the term "Eureka Truck & Specialty" does not appear anywhere in the document. It could've been un-assigned and patented under something else (e.g., folding wheels, etc), but I haven't gone down that path yet.