More Robert:
The stock hardware does fit the aluminum end bell. I placed the hoods and bottom plates on the end bell and used toothpicks to align the hoods, plates and end bell screw holes. Interestingly, I used a set of the stock hoods and plates (*not clearanced), and they don't seem to project further inside of the end bell aluminum than the internal limits of the end bell. So it would seem that whoever designed the end bell may have moved the holes further out by a few thousandths so that further clearancing is not needed with a nominal .200" O.D. (is: typical modern sized) com. I will recheck all this when I build the first arm of course, but now I have to find where I put the darned insulating washers and 0-80 screws.
On your questions regarding dimensions:
*Both the stock plastic end bell and the aluminum version have an O.D. of approximately .765"-.766"
*The can I.D. at the flange measures slightly smaller at .763"
This makes sense in that, for a tight "snap-fit", what is actually happening is that the can is being forced to deflect outwards as the end bell is inserted. What I don't like is that, after inserting and then removing the aluminum end bell, the anodizing on the end bell was slightly marred. I suppose that what really matters is that each side of the hardware is insulated, but I'm wondering if the inside of the can flange should be polished/deburred, or even slightly relieved for a "slip-fit" rather than a "snap-fit". This is a good example of why I would love to hear from people who have used these as to proper methods and practices. As in winding and armature-building, it looks like I'll have to find out for myself by trial and error, and document it here so others have the information.
ProSlot p/n 641/642 hardware fits the JK aluminum endbell with a little fiddling or use the kinda junky stock plated aluminum hardware from either the JK or ProSlot plastic endbells.
As per above Jim, the JK hardware fits fine. The hardware on the JK and PS minicans can both benefit from some flattening and straightening, and that gets more important as the motors are asked to play well with hotter arms, but that's to be expected. One minor correction, the hardware on the Hawk is plated brass. When you flatten and sand these things as I often do, you will find "yellow metal" is exposed under the very thin plating. What I'm not particularly thrilled with concerning both the JK Hawk and PS4002 hardware is the very short bearing surfaces for keeping the brushes aligned. Between that and the sloppier forming of these than even typical C motor hardware, you can wind up with brushes being everything from too loose to bound. On such affordable motors, this isn't a surprise. When the motors get "more serious", then it's a good thing to check out the hoods. Even the bottom plates, which are stamped "flat" metal, can have some noticeable tweaks in them.