Need advice on how to repair rust holes in bed floor

[wHATANERD]

Hello everyone, I've recently started a restoration on my 69 Long Fleet Side and after sandblasting the bed floor I found two spots about 1 foot x 1 foot square that have numerous small rust holes. ( most likely where the PO had a tool box or fuel tank mounted) I had a piece of a patch panel ordered from LMC that I got from a friend, however it's too thin of sheet metal, and the height between the peaks and valleys of the surfaces is too shallow. I ordered another patch panel from another vendor, and it is not much better. Has anyone had any luck finding a good aftermarket panel for repairing a bed floor? I've attached a photo of the worst spot that need repairing and also was wondering how others have fixed similar rust spots. Any suggestions would be greatly appreciated.