Well I went ahead and drilled the shell. I measured like 10 times before hand...just to be safe. It came out awesome, and it still sings like Marvin Gaye. I really wanted "Gretsch floor tom brackets and couldn't find them anywhere...but it dawned on me that the brackets on my "Rims" and the floor tom brackets were on in the same. All I did was unscrew the brackets from the rims that I am not using...(12" tom is on snare stand, the new 16" tom which I would not use the rims, and an 8" that I do not use), and purchased Gibraltar 12.7mm floor tom legs. What I did to drill the shell was as follows.
1. I measured many times to be sure the spacing was how I wanted and that the brackets would be level and plum.
2. I used the backing plate and gasket to mark the holes as a template
3. I fixed (3) pieces of duct tape to the inside of the shell opposite the location of the drill holes.
4. I used a small drill bit (about half the size of the final bit) to first drill the pilot holes...and then double checked the gasket template to make sure the holes were centered. I also used a small wooden scrap 1x2 on the inside of the shell (over the duct tape) as a brace for the drill.
5. I then drilled the final holes with the appropriate size drill bit and attached the brackets and legs.
I will attach pictures later this evening. It really did come out awesome. I would have used the dynamount floor tom suspension, but I was short on time and money. Thanks for all your help.