Paul, I have no idea as for mintage. Wish we all knew. Seems anyone who wants a set has at least two sets. There are seemingly always at least one set on FeeBay for $175 and up. In fact I was just offered by a long retired collector 4 sets at $140 each delivered. Still undecided if I will help the seller out and buy them. Not to interested at that price of $140 but I may be interested at like $120, just over melt.
I did win my first set on the .25 cent machine. You had to play 3 quarters just like the strike machine to win the set. Other wise you just got cherries. Mine cost me $17.25. I got lucky and was a very happy player. And yes it was a hand pay with paper work that had to be filled out and signed for.