1990 World Record Commemorative Plate on LT5

[bobby]

I'm a bit baffled because I have never seen this plate (see attached photo).


I know that the 1991 ZR-1 and coupe got a "24-Hour" rear window decal.


Was this VIN-matched metal engine plaque only on 1990 ZR-1s? Or did the plaques also get used in 1991?


I will assume that the earliest they were used was mid-March 1990?


Any idea of either VIN-start or date-start for the plaque?