Viper is correct - Humpty Dumpty is the first with EM flippers.

From the historical materials I've read, my own personal opinion is Double Shuffle came out at a time that didn't necessarily need flippers. Pinball was only about a year old, was a huge hit and used for gambling. Everyone knew it but the laws and moral brigade hadn't caught up yet.

By 1947, the depression was over and the war was won. Pinball was getting banned left and right and the mafia was heavily involved. Pinball needed a silver bullet to evolve in a way that would help resolve it's legal/criminal issues but also stay popular with the public. That's why EM flippers were such a hit when they were.

I got to play Double Shuffle once and it's pretty cool. It's a very elegant-looking game and more fun to play than most pre-flippers, because a pre-flipper without the gambling element often loses a lot of its appeal. If they were produced today I would probably buy one over the bagatelles a few companies make.