I just bought a Data East Jurassic Park this weekend. There are no EOS switches installed on the main left and right flippers, which seemed odd to me. Looking at the flipper board, I believe the EOS pins have been jumpered together for both sides on the IDC connectors to the board.
The manual seems to indicate that this is to be expected from the flipper diagram on page 38 (no EOS switches are shown), but it does say that the left flipper should have a switch 180-5124-00 on left only. Looking this up indicates an EOS switch, ostensibly to maintain flipper power during a Raptor Pit shot return.
I'm guessing I could get by without the EOS switch unless I get annoyed with the Raptor kicker causing the flipper to drop slightly.
Thoughts from other Jurassic Park owners? This doesn't seem like a big deal, but I don't want to ruin my nice game.