Here is an example of a 1983 Washington State Patrol Mustang (unconfirmed agency usage) that resurfaced recently after having been added to the SSP VIN Project last year when it was for sale -
http://www.specialservicemustang.net...info165404.htm
The new owner has posted up more photos, which were added to the car's page. Note that there is a 2nd Buck Tag, even though the car was painted a single color (there had been some talk about the early single-color SSPs not having a 2nd tag). The second tag only lists the DSO number, but I think this is the first early, single-color SSP we have seen that has a second tag. Pretty cool!