Yes, the unpainted plate, welded to the replacement king pin seems to be the design for the Dearborn N series front end loaders.
Have found Dearborn parts manuals where this replacement king pin/plate weldment was bolted to the loader frame.
Have seen this same plate/king pin in operating manuals with 9N riveted center support and the 8N welment center support.
Have studied many archives where a guy bought a Dearborn loader and could not figure out to attach it to the front. Nothing fit. Believe they finally realized the original king pin would have to removed.
If you look at the design of the NH 1500 utility tractor, JD utility series 1000,2000,3000 all have fixed front axles to the frame.