Circa 1979. This a partial selection of the dice I bought to replace the original polyhedral dice that I owned. They are made of a better grade of plastic but there are still no D10s and the D20s are numbered 0-9 twice. I purchased no D6s for these sets because by this point I had raided all the other games I had for normal D6s.
Notice how the D4s have had their points removed.. You can still see how the plastic chipped over time.
The infamous Demon/Orc dice. These are from about the same time period.
I always tried to paint the numbers using a toothpick and some enamel. Sometimes my results were less than great. I also tried to paint the twenty a different color than the rest of the numbers over 10 (hence the red zero). The first D20s that designated the difference in sides had a simple plus sign on half the sides.
Below we have one of the first ten sided dice produced. Notice how it is really a twenty sided die with have the sides elongated and the other half reduced. I bought this one at a local convention more as a novelty than anything else.