Walthers Great Circus Kits

[tcf511]

I just acquired a few of these cars on eBay because I want a circus train on the layout when the grandkids come to visit. Some of them were already built up and some were in kits. Some kits had one car and others two. It appears that there were multiple series' of kits with 12? kits per series? Can anyone tell me a website where I can find out more about these kits? Specifically I would like to get a list of what cars were in each series and if accessories like the human cannonball truck were sold with a kit or separately. TIA