Trunk taillight protective boards Identification

[WT6066-2600]

Today's garage discovery,

Found these boards back in the 80s and stored them away.  Never knew if they might be original to 68 Shelbys.

One side is a flat black paper texture and the other side is a gray-blue somewhat smoother texture.  Also the shapes are different, one is longer and the notches at the top are spaced differently.   

[Coralsnake]

Yes sounds like a proper description

[TLea]

Do they have a makers mark stamped into them in one of the upper corners?

[WT6066-2600]

No stamped markings

[TLea]

They can be hard to see as they're not an ink stamp but they're pressed right into the material

[Special Ed]

Its a small circle look at bottom photo upper rh  corner.

[WT6066-2600]

On both blue surfaces there is a circle with some impression.  Thought it was just an abrasion.

[TLea]

On both blue surfaces there is a circle with some impression.  Thought it was just an abrasion.

Thats it. OEM

[Bigblock]

The boards that were laying in the trunk in my KR have "FP" stamped into the corner on the grey side. Too fragile to try and install.