Response from Fred Dahlinger: Your parents are best known today for having owned several bona fide circus wagons that were from one of the King brothers-owned railroad shows. After a couple transactions, they ended up at Circus World Museum.
I never had the pleasure to meet either of your parents, but they were known to some in the trade, and did do some circus visiting. They traveled with Carson & Barnes Circus in 1986, per a mention in the season's route book:
https://digital.library.illinoisstate.edu/digital/collection/p15990coll5/id/13768
The principals and much of the management has passed on, but the Byrds may recall them, or perhaps CHS member John Polacsek, who spent much time with it. Their 1950 circus operation, identified as Robinson Bros., garnered some coverage in Billboard magazine, found here:
https://books.google.com/books?id=n_UDAAAAMBAJ&pg=PA60&lpg=PA60&dq=%22arvel%2Ballread%22&source=bl&ots=4forzbiJaS&sig=ACfU3U1adgnN1pI-k7uJAmsZTktXdhxsxg&hl=en&sa=X&ved=2ahUKEwijzLr5mYnxAhWTG80KHc3lD8AQ6AEwEnoECBUQAw#v=onepage&q=%22arvel%20allread%22&f=false#v=onepage&q=%22arvel%20allread%22&f=false
At about the same time that they were operating their Great Pan-American Zoological Exposition, in 1948-1949 W. F. Duggan was staging his Pan American World Wide Animal Exhibit, another tented animal presentation moving on trucks. It was in the Midwest and Southeast, far distant from California. 1949 and 1950 couriers from this enterprise are at Circus World Museum. Like your parents exhibit, it also had a single elephant. Someone will have the life story of your parents elephant, Susie.
I would look to the California fair community to locate people that may remember your parents and their operation. There is likely a statewide fair group and often they have a membership list, newsletter or annual conference that can be consulted. Bear in mind you're seeking people active 70 years ago---they'll be in their 90s.
Besides your parents collection of documentation, you might also look for collections of fair material at California institutions. It's also possible that local newspapers may have interviewed them about their beasts and revealed more about their life existence.
I don't know if Roger Smith, who was around animals in California for many years, may have known or will recall them. To the best of my knowledge, only large artifacts were preserved from the Louis Goebel's site.
