I spoke with Stephen Diamond (Diamond Ambulance) today regarding my Criterion. He recalls purching it in MD; either from the fire department or the coach / ambulance dealer in the 1980's. He said that he paid a PCS member to drive the car from MD to TX.
He kept the car in his ambulance museum during his ownership. Although it may have seen service during one of the big storms that hit the gulf. He sold it, and 4 other ambulances to a collector in S. CA. That person kept the cars in storage for a number of years, then sold most of them. I purchased it from one of his buyers. Neither of them had transfered the title from Stephen. When I registered it, I had to turn in its TX title with Stephen's signature on it. So I have 36 year old car that has only transfered ownership 3 times on paper.