What are These Stamp-Like Things?

Factual Questions
1

When my grandfather died a few months ago a bunch of us were going through his personal effects, and I became the proud owner of two sets of stamp-like things.

One is a perforated 8 X 5 array of stamps that are about an inch square. The other is a similar array, 5 wide, but is only 5 high - I’m going to assume that’s due to use of the stamps.

The stamps are a kind-of orangish-brownish-yellowish color and have “C8” written on them in big black type. Above the “C8” is an 8-digit number in green. The upper-left stamp on each array is the highest, and the lower-right is the lowest. Below the “C8” is the world “MILEAGE” in smaller type, also in black. Below that is a blank line, and below that is this: “(License No.) (State)”

I’m assuming that these are related to WWII gas rationing. Can anyone confirm or deny this?

And do they have any collector’s value?

EDIT TO ADD: A google image search confirms that they ARE gas ration stamps. What did the C8 designation mean? And do they have any collector’s value?

2

The Master Speaks!

3

I have only a partial answer for you. Some stamp collectors, rather than saving a whole sheet, will buy the corner of the sheet. If I remember this right, it’s called a plate block, and it’s the upper left hand corner of the sheet. I don’t know the rest of the answers, and heck, I might be wrong about this fragment. My FIL worked at the post office, and he’d buy a plate block of each new stamp. I’m not a stamp guy, myself.

4

I have a bunch of them, but I think they were in a box of stuff I took to my parent’s house a few years ago (they were my dad’s parent’s stuff). I have no idea as to value, I’d imagine there are a lot of them out there.

5

They have little to no collector value. They exist in plentious quantities, and very few people collect ration stamps from WWII.

6

I’ve only heard of **postal **plate blocks, in fact I used to collect them myself. And they weren’t necessarily the upper left corner of the sheet; they were the corner that had the plate number printed in the margin. Actually the sheet of stamps would be cut from a larger sheet which had a plate number in each corner, and if you had a plate block from all four corners it was called a “round robin.”

I don’t know how much of this is still applicable, with today’s printing technology.

And I don’t know whether gas ration stamps had plate numbers.