1) Laser War has nothing.
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2) Secret Service
I cannot find anything in the Secret Service manual that says anything about a knocker.
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3) Torpedo Alley shows a knocker at ED 58.
Screen Shot 2019-08-09 at 4.01.46 PM (resized).png
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4) Time Machine has something called Klacker Warning. I doubt that a Klacker is a knocker but I don't know what a klacker is, either.
E Ad 59
Screen Shot 2019-08-09 at 3.55.02 PM (resized).png
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5) I found the knocker on Playboy 35th.
It is E Ad 54 down at the bottom of the page.
Screen Shot 2019-08-09 at 3.48.19 PM (resized).png
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6) Robocop has nothing.
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7) Phantom of the Opera has nothing.
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First seven DE pins show two with knockers; one with a Klacker ???; four with no knockers
Bummer. I would like to have a knocker on my Robocop.
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Interesting. JP manual shows nothing for a knocker that I can see.
Screen Shot 2019-08-09 at 4.28.23 PM (resized).png
Hook is the same way. I cannot find anything about a knocker.
Simsons does not show a knocker, either.
I'll need to study the switch matrix's when I get a little more time. If your pins have these knockers on it sure seems like there will be something in the manual somewhere.