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Monday 8 January 2018 at 21:13
Quoted from nicknack66:Maybe Williams first used the square bezels on the run and then switched to circles?
Most likely it was they ran out of the supply and had to keep the assembly line going.
Gottlieb's games had circles... so I guess they used there supplier.
Source: http://pinside.com/pinball/forum/topic/blackout-club-fans-welcome/page/6#post-4164688