273 commando Build
I think these head gaskets are what was on my first D/Dart. On my tablet, I measured the silhouette left on my block with the bore set at 3.63. The seal ring was just about 4.00. The material looks like it would compress quite a bit. So I'd say the NOS gaskets that you just got are the correct ones. The 1198 stamp must be the date code ... 119 day of 1968?
Just did a check on the head gasket on "The Politician" and it's just metal and about 0.023". Just enough of it was sticking out of the front to mic it.
Did a part number check on MyMopar of the 2536757 head gasket and nothing came up. They have a database of over 120,000 Chrysler part numbers.