The 37D motor bracket has a picture with some measurements:
pololu.com/catalog/product/1084
Unfortunately, it doesn’t have everything set out. For example, what is the lengthwise distance from the edge of the bracket to the center of the first hole?
There are three ways I could conceive of the placement of that hole:
- Assume the edge is the center of the “zeroth” hole, so edge-to-first-hole-center is (hole spacing.)
- Assume the edge is the “close edge” of the “zeroth” hole, so edge-to-first-hole-center is (hole spacing - hole radius)
- Assume the edge is a mirror line between the “zeroth” and “first” holes, so edge-to-first-hole-center is (hole spacing / 2)
And, because when I assume, I make an ass of U and me, it’s probably something else entirely. Which is why it would be great if someone could tell me what it is 
Another missing dimension is the offset of the center of the motor mounting pattern from the rounded top edge of the bracket. It could be centered on the face, but it could also be aligned with the edge of the motor and have a fixed margin to the plate of the bracket. If someone could post that measurement, too, that’d be swell! (I’m assuming center of cutout for the drive shaft is centered on the motor mounting center – but, again, that’s an assumption, too!)
I have marked out my “best guesses” on the drawing here:
?a – guess 4.76 mm
?b – guess 18.80 mm
?c – guess 3.30 mm
