Mike:

It would be easier if you posted photos of the markings you are reffering to. Then we can probably give you some information.

I will throw this out there, on later Oil Bottles there are 'Embossed Seals' from certain states. These seals prove that the bottle in question was inspected - and passed - by the state indicated in the seal, as holding a full quart of oil if filled to the indicated line.

Later . . .

Jim