Here is a stock GC4 pocket. The OP has a Tournament Edition. It's not even in the same ballpark between my pockets and his pockets.
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There is some parallax in this ruler picture, it's closer to 5 1/8" than 5". I couldn't get the camera to show that.
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Depending on exactly where "on the tit" the ruler or the caliper is placed, I can get a number between 5" and 5.125" (5 1/8").
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The OP's table is correct as a Tournament Edition. His ruler picture aligns exactly with what Brunswick specifies.