hahaha...I know it sounds odd, but yes, the Prelude Bracket fits our bumpers better and the fog sits a little better compared to the Civic/Integra rear fog.
Will post pics, although I haven't taken pics of the inside of the bumper, when I move the car again I can take some of those as well.
There is no marking inside the bumper since it isn't something that is stock on our cars.
You have a Coupe, so the measurement will be a little different, but the guy who did mine, and almost every other one of the Toronto Accords, has a good eye for it. Not sure what marking point he used on the Coupe, but for the sedan, he went by the tail light and used a starting point to mark off where to cut.
If you pm me your number, I can email you a couple pics I have on my phone.