Just my experience, i have never seen a bracket like this on any CB750 frame.
However, I appreciate your observation, paint and welding appear original.
Questions i would answer (to determine originality) by careful examination:
1. Does paint on bracket and surrounding frame area appear unmolested ? In other words, does bracket and/or frame appear to have ever been repainted ? What color is base coat (primer) under black paint in area of bracket and other parts of frame.... (is color of primer same?) If primer color same, then one could argue bracket is original. If different color at bracket than other parts of frame, then one could argue bracket not original. (Hope what i write makes sense !)
2. Is weld steel or brass ? (If i remember correctly, frame welds are steel. No brass welds.....)
Cannot imagine why Honda would weld this bracket, during frame assembly, to the frame. I am not aware Honda, had available a steering stabilizer as a single accessory or fitted a stabilizer on assembly line, during the time K0's were manufactured. (As someone wrote earlier, APPEARS to be for steering stabilizer because of position and hole in bracket.) I am not aware the CR750 kit, offered by Honda, contained a steering stabilizer in the kit. My limited knowledge of the CR750 kit, this kit was not available until sometime 1970. Pictures i have of the CR750 kit, does not show a stabilizer as part of the kit.
Will be good to hear again more from members. Or, you could email Vic World with pictures and question.
