Adam, good to see you over here.
I'm the one that contacted you @ stangnet about your car.
The SC units that were painted the highway patrol colors are stamped "PAINT GREY W-2813" (1989) or "PAINT SPECIAL GREY W-2813" (1990) on their buck tags. I couldn't find W2813 paint code but I did find a Ford fleet color "Grey" in 1988 with the code WT2813. W2813 was the 1st 'special' paint color on the door tags.
The second paint code on the door tags seems to have been different every year.
SC Hwy Patrol 2nd 'special' paint color:
1989 = M6062 (Light Grey/Smoke)
1990 = M6330 (Light Titanium)
1991 = M6401 (Titanium Frost)