I was thinking there used to be a supplier at Claremont ... yes, that Claremont. I'm going to go there someday just because it is one of the few little towns in SE IL I have never been to.  Anyway, I can't think of the name and haven't had any luck searching for them.  A Google search of nurse trailer came up with several ... umm ... interesting results.

GVM Richland at Decatur has them listed on their web site (go to http://www.gvminc.com/ and click on nurse trailers). Sprayer Specialty has them listed (see http://www.sprayers.com/tandem_nurse.htm) So does Schaben (http://www.schabenindustries.com/nurse.htm) and Linco from El Paso, IL (http://www.schabenindustries.com/nurse.htm)  Loepky has them on their web site (http://www.loepkymfg.com) along with some other very interesting stuff.  But they may be farther than you want to travel.

Have you tried Phil Jensen at Newton?  His web site is under construction but you can email him at [email protected]   I think in southeastern Illinois he would be one of my first calls to see what he has.