Hey Rick,
So don't do a bunch of tests yet. Things like the "bulgy" aspect can easily be changed.

I think the main part first is to see if the "hollows and solids" are as they should be along with the basic dims. (For instance, I made the walls 3mm thick. You just said 2.5mm, so that would have to change still). Look at how the 15 mm solid is made and mention if that's correct. After those are all correct, we can look at a file where you get the shape you want. Even set you up to do some variations yourself. (Like note Paq's shape has not the same dramatic bulge) You'll see me set the sphere at an exact 45 angle. Is this non-negotiable? A slight rotation back on that would remove a good portion of that bulge, fairly easy.

Also, with regard to the 27.5 radius area (Where the "sphere meets the body"..... There will be a difference in that area being some sort of sweep or flow through those dimensions, and getting a curve of something "other than a perfect 27.5 arc", but that doesn't mean it's not conforming to those dims. The construction will be much more limited if you "must have an exact arc there".... Just a note.

Talk later.