A search of my Lynch Road data turned up the following for broadcast sheet/window sticker comparison to the trunk marking:

VIN BS/WS MARKING

214177 T82 F70 W
279720 T82 70 W
220739 T83 RED F70
188062 T85 RED F70
166637 U64 F70 W
194789 U65 RED F70X15
253197 U65 70 X
256700 U65 F70 X

Looking at the T82 and U65 codes, you can see the different markings. There was obviously not a consistent process for doing this mark. Many of the A12 cars have a 70 X designation along with other "RED" designations. Attached is the 69 tire code for easy access.

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