I don't think I have seen that one either. I looked in detail at all the turntable shots I could find when I was working on the design for ours.
A couple interesting items to note from this one: There appears to be no outer rail, it is just supported on blocks of wood. If the truss rods are tensioned enough, the outer part of the turntable won't touch until the engine comes on, which is essentially how ours is set up. Also note the tilting of the fourth cross beam from the end on the underside - that is due to the attachment of the inner truss rod. All of the original turntables had that problem. I deviated from the originals with a cast anchor for that truss rod, due to this problem.