Stump Grinder Slant 6 Starter

I'm just now putting my '64 D100 back together and realized that I have the same 1889100 starter (including the same G1889067 head casting) on my slant 6. I've returned three different starters to Summit before I figured out what the heck was going on.

I've been digging into this starter and can't find many cars & trucks that used this one. Fwiw, my truck (which my grandpa bought new down in Charleston when I was two) has been in our family since it rolled off the lot. So I know it's the original motor and whatnot. Most 225s had blue or red painted blocks, but mine is one of those with the yellow engine. I've been told that different Mopar plants made the slant 6s and they each had their own color scheme. I also know that there were/are fewer of the yellow-painted 225s, like mine. Makes me wonder if that had something to do with the type of starters used.