Carl,

They are the same chip. Don't let the condition of the chip itself fool you, look at the condition of the hot stamsp. The chip on the right looks to have a good strong hot stamp. But look at the chip on the left, you can see the green showing through in several places. It was gold at one time. I'll bet a nickel that if you look very carefully with a good magnifying glass, you will still see traces of the gold in some of the edges and points on the letters.

Since they are just 50c chips, why don't you try this. Spray a little windex on the gold one and scrub it with a toothbrush. It will soon look like the silver one.

Greg