I sent the guy and email in case he wanted to reply to some of the questions here (like I said, he was a good seller).
Here's an excerpt (with some editing to make it clearer):
" I understand the possible confusiuon with the buttons. I can only fit so many letters in the auction title description.
I have made the decision to eliminate the Betson-Imperial buttons I sell. I have placed them on sale at .99 cents starting today. To be
competitive and similar with other larger companies I'm only going to carry Happs Competitive joysticks, Happs Competitive convex buttons and Happs old style concave buttons. You will see the new Happs Concave buttons on e-bay next week."
The main thing I got out of this was that I'm going to buy a couple of extra buttons. I like the first set I got and although I can't physically compare them to the Happs, they seem authentic to me.