74 = Regional code for Seattle/Portland I believe. :)

Correct.

74 = Seattle district sales office

All Ford DSO codes are here: http://www.specialservicemustang.net/DSO.html
(Some for Mercury are different, depending on model year.)

And the PCSD buck tag decode:

PIERCE CO. WA. = Piece County, Washington (sheriff)
D.S.O. 74-0092 = Seattle district sales office (74), 1988 model year special order # 0092
D.S.O. POLICE

0220 = rotations #0220
66B = Mustang 2-dr coupe
LX = LX model/trim level
ET = EFI H.O. 5.0L V8 engine (E), automatic overdrive (AOD) transmission (T)
256171 = 156,171st 1988 Ford scheduled for production at Dearborn Assembly
AC = manual air conditioner
HB = heated backlite (rear defrost)
3R = medium shadow blue Metallic exterior paint color
DL = power door locks
SK
FB = cloth seating, low-back buck fronts (F), Regatta Blue interior trim color (B)
JF = 1988 model year (J), Dearborn assembly (F)
0516 = May 16 scheduled build
740092 = Seattle district sales office (74), 1988 model year special order # 0092
3R = medium shadow blue Metallic exterior paint color
2
256171 = 156,171st 1988 Ford scheduled for production at Dearborn Assembly

For my clarification (as well as everyone else too), is the special order number specific to each DSO for a given year, or is it the Ford special order number that year? Stated another way in the following example, could cars from DSO 24-0123 and DSO 72-0123 have been produced in the same model year?

I believe it is the special order number for that year. So no, you cannot have a the same number in the same model year.

Thanks Mick. I was a little fuzzy on that detail, so I figured that I would ask... :)

BTW - if it helps anyone who is interested - I know a LOT about this car - knew the former owner here in WA. I also know the guy who used to drive it when it was in service (he bought it from auction years ago once it was retired) and can act as a connector if needed.

Very nice. Was well cared for. And is rare. Was a 1 of 1 car with PCSD - their only blue one they had.

Would be a nice turn-key car for someone. And, the seller is a good guy. He and I have been chatting in the last week since he put it up for sale - and is pretty much as it left WA a year ago. Has some gear with it, too.

Could be a nice ride for someone.

I have a twin to that car here at the house - but mine is a total bucket (needs everything) and was one of the marked units they had in red. This one's a gem in comparison.