You're right, Mike. Plus there are some Never-In-Service SSPs that have VERY low miles. However, I see what the seller is trying to say about these cars. Typically, a collector car is more desirable if the mileage is lower, but most SSPs are rich with history (even if it is unknown), which usually offsets any concerns about them having high miles.
I sent the seller a text, and he said that he would send me over some pictures of the VIN label and buck tags.
The only other (possible) 1992 Nebraska SSP we have confirmed in our VIN Project so far is...
http://www.specialservicemustang.net...info148737.htm
...which is unconfirmed as a Nebraska car because the buck tag only says POLICE. Perhaps the seller of this car has some documentation that will confirm the other SSP?