A-7.
I got my spheres from Plastruct.com When you visit their web site, just make sure you look carefully at their charts which give you several dimensions on the spheres themselves, like inside and outside diameter measurements.
I wanted to add my Polar Lights 1/1000 Enterprise nacelles to my Daedalus/Wasp class vessels, but I'll have to modify them a bit so they wouldn't look too advanced. I don't have the skills to make "accurate" ships yet, so kitbashing them is the best approach for now. Also, modifying the nacelles would throw off anyone trying to comment that the nacelles and ship scales do not match :P . If I were to display a Wasp class vessel at 1/1000 scale next to PL's Enterprise, it would be just a bit over 5 inches long, its main hull being about 2 inches in diameter. I would love to know who would make decals that small. It owuld really be a jewel.
Happy Kitbashing and ignore the typos :P
Riö<*>