[chris]

I don't think anyone can give an accurate number only guesses. I have had several GM's sets and singles over the years. They have always been one of my favorite post war sets. I heard or read somewhere that there were an estimated 20,000 of each card printed in the late 1960s and early 1970s. So if there are around 650 cards in each set that would put total production around 13 million each year. The GM set was a "test issue" per say, but there are many more GM than many other so called test issues. I would guess there is probably around 5% or less of the GM compared to the regular issue Topps. My guess would be around 55,000 total GM cards. With the double prints accounting for at least 75% of the total GM production. I have put several sets together, I feel there are some SPs that seem to be much tougher to find than some of the other SPs, such as, Howard, Killebrew and Wilhelm to name a few.
My guess
55,000 total GM
40,000 Double Prints.. 22 different cards.. 1820 of each card.
15,000 Single Prints.. 33 different cards.. 455 of each card.