I use two different models of the Ludwig 1400 flat base cymbal stand. Both have the tear drop shaped tilter. One secures the legs to the bottom tube by using a wing bolt attached to a collar. Loosening or tightening the bolt allows the legs to fold in or out. The other employs a wing bolt and large washer to loosen or tighten the legs to a circular base. The bottom of this base is stamped 'Zinc Die Cast" with the numbers 2423 also present. I have always believed the circular base stands were earlier, maybe early to late sixties and the ones using the wing bolt on a collar came around the late sixties to early seventies. I certainly am no Ludwig expert though! If anyone can clarify the time frame for me, I would be very appreciative. Thank you very much.
Brian