Will,
Pretty sure my tank area looks the same as yours (see attached pictures). The holes are new, by me to see if the ply under the glass was in decent shape.
I've also included a pic of someone elses boat where the owner has removed the top layer of glass and the rotted ply floor under the tank. What you see is the center stringer and the inside of the bottom of the hull (the white PVC is the owner's recent addition-not original equipment).
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