The gasket composition of the intake manifold as removed appeared to have the same matrix throughout. It was an odd blue green color and left its color on both the intake manifold and the engine which was removed before installing new gasket with solvent. It had become somewhat brittle and had slightly extruded itself into the flow path to a few cylinders.
The new Beck/Arnley gasket part number 039-6312 is thicker measuring 0.091 inches thick and is a one piece. Made in Great Brittan.
Trimmed to fit each flange of the manifolds. There is a similar blue green color on one side and a black softer material on the other sandwiching a much thicker white material. Not sure but both the outer layers appear to be only 0.005 inches thick. Half that of a match book cover if you will. Installed with blue /green side against the intake manifold and the black against the engine. Torqued carefully.
I like them and the engine has no intake manifold leaks.