spheroid

They are string through the body design, so most of the string tension is focused downward across the saddle. The screws are just holding the position. Their placement is irrelevant.

I thought about this and you are right. The bridge wants to go down (obstructed by the body) and towards the nut (which it can´t because of the screws), so all the screws come in to play. But I still think the 3 screw version looks better.

I don't know what they mean with 'single size' pickup but it's definately suited for humbuckers. It's the bridge ibanez uses, like on this RG...

but I would rather go for a bridge with a 3 screw mounting pattern under the saddles, like on this fender.

The 3 screw version looks better, and the place of those 3 screws is exactly where the tension is. With the gotoh version the tension is on the back 3 screws, so you´ve got the tension on smaller screws.

First one of my pet peeves, it's Randy Rhoads not Rhodes. Second, I don't like tune-o-matics. I like the string-through fender fixed bridge style like on american hardtail strats. It doesn't fall of without strings, it can accomedate every fretboard radius. If your RR is a jackson it's probably 16" while TOMs only come in 12". And you don't have to recess it or change the neck angle. Also it has a wider intonation adjustment range. Usually TOMs are not recessed so the strings on a gibson are further of the body as on fenders, I like my strings closer to the body. So that's what I would go with. If you do, go with the one with 3 screws under the saddles. There are aftermarkt ones with screws on the corners, but that's a stupid design.

Nice project, can't wait to see how it turns out. I like the idea of a 7-string radius.

Titebond can be purchased from Vox Humana (voxhumana.nl), online-shop under 'gereedschappen en lijm' but is expensive (€15). It's also available from Stew Mac for $7.97 and isn't listed as flammable, so if you need other parts from them as well it might be an option.