Passenger Trains > B&O sleeper question

A group of "bird" B7O 16-4 sleepers built by Budd in 1954 (7100 to 7110) went to Amtrak via the SCL and ended in the group 2530-2537 retired in 1984. One of these cars were sold to Ringling Bros and became its RBBX 41409. My question is: Which ex-B&O (Amtrak) car became RBBX 41409?

7104 Mockingbird and 7103 Kingfisher were purchased by RB&BB. Bob

I have down that 7103"Kingfisher" became RBBX 41402 & it was on the 2002 blue unit.
7104"Mockingbird" became RBBX 41401. It was not on
either the red or blue units the last several years I saw the train.
neither of the above cars were the configuration
you mentioned though in their original form
I do not have a RBBX car with #41409 on my list, but there certainly could be one.

SP 3201

MORE INFORMATION
according to a detailed amtrak list I have cars
2532 Gull,2534 Robin, 2536 Thrush, 2537 Wren, were
never given these amtrak numbers so I\'m assuming
they were parted out to keep others running.
Car 2535 Swan was in a wreck and sold to Anbel
Corp in 1981 , who I believe is a scrapper. Hopefully this can narrow your field.
It looks like none of these were HEPed so I\'m surprized they even hung around till 1984.

SP 3201

http://www.iltransit.com/sleepers.html