According to the Northland PCS board, this Criterion was *the* last Criterion ever built. Here's a link to it on the Northland PCS site:
http://www.northlandpcs.com/criteriongallery.htm
I actually lived in Mt Morris, IL from 1995 - 2000, and in the late 90's I spent many hours in the Mt Morris library basement going through archives of the Mt Morris Times to research a historical project I was working on at the time.
The Mt Morris Fire Department purchased their first ambulance, a 1958 standard headroom Superior Cadillac, in 1958 from Foster Coach sales in Sterling, Illinois. Prior to this first ambulance, ambulance service was provided by Finch Funeral Home.
In the months leading up to the Fire Department taking over ambulance services in the 50's, there were several news stories about the need for a community based ambulance service because the nearest hospital was many miles away, and the community really got involved with letters to the editor, full page editorials, and Foster Coach even got involved and started advertising with full page newspaper display ads of Superior ambulances...in the newspaper!
They used this Superior for about 10 years or so, when the ambulance started aging and breaking down a lot. Once again the community got involved, apparently the ambulance lost its brakes on a run when they were halfway to Rockford Memorial Hospital and it was deemed unsafe. So they did fund raisers, Foster Coach once again started running full page display ads of various ambulances, and in the late 60s Mt Morris once again purchased a brand new ambulance, this time it was a red and white Superior Cadillac high headroom. There are several pictures of it in the newspaper, with the fire department proudly posing in front of it.
I didn't do anymore research after that, but can only assume that about 10 years later, they ordered the Criterion from Foster Coach.
Abe