[Entropy11]

I noticed a pair of holes in the trunk floor in the vicinity of the fuel filler neck (‘68). When I look online I see many trunk pics with apparently no holes in the floor in that location. It wasn’t easy but I did find a few with holes and one even shows a support bracket? Was this common?

Below are some pics I found with/without the bracket. The first 3 are actually from a Chevelle site. The next showing the holes filled with only nuts/bolts and washers was listed as a ‘68 GTO. The last pic was just a GTO with a new tank, probably new floor, and no signs of a support. The Any ideas?