Hi Terry, here's a picture of my '53 dash which is original. The '51 dash has one difference and that is the windsheild wiper knob; on the photo below, the wiper knob is mounted on the dash face, above the ignition switch, whereas on '51 and '52 Js (all models) it's located top center of the dash. Other than that, this is how they were originally -
Add-on accessories such as overdrive and heater, were mounted below the dash using chrome hangers. The vent controls actually passed through the steering column molding as shown in the photo.
Let me know if this helps.