Neil, there is a thread on this at VFF in the Fine Points Form 4-9-2018Bob
Some were used until early 29, mine has the two cups. Gary Karr's Tudor built about a month later has the bar. I think it was a matter of where the car was built and inventory on hand.
BTW, when you are ready to let go of those bars let me know, I'd be pleased to take them off your hands.
Bob, I had no luck finding the thread you noted. Can you help?
denniskliesen, my intent is to sell the seat (including the bar). I only have one seat.