Here are some pages with pictures of circus bandwagons:
http://www.vintageviews.org/vv-3/t_land/pages/trl02_002.html
http://hartlandsmith.tripod.com/parade.html
http://www.december.com/places/mke/images/bandwago.jpg
http://www.circushistory.org/Bandwagon/bw-spec2.htm