They were very helpful in assuring me the part I needed and was about to order was indeed the right one. Thanks for great customer service!
Center post-rght-for ada/asa/aua71/7112
4-121r, center post 10-9/16 x 34-9/32, 71 series
Buy this part and as many parts as you like and pay only $9.99 shipping, within the Contiguous United States.