So the new holes are central to the old ones.
I'm thinking of trying this, i have'nt had any problems whatsoever with the MM bridge and that is an almost identical set-up (saddlewise) to your picture.
And its not like the mod would ruin anything.
I'll price-up at wd music products, would you suggest applying grease to new parts to help against grub screw movement?
Incidently i looked into the TOM idea...seeing how things lined up etc with the tom off my flying V. Even with the tom flat to the body the neck would have to be shimmed quite a lot to get the action lower where the neck meets the body, it was way high. Plus would the bridge be grounded without the post screws going into the mounting holes because the tape on the post mounts disconnects any connection.