Thanks, Tucker. Ok, there you have it.
"AMO BOW SIGHT & ACCESSORY MOUNTING HOLES STANDARD
Two holes located on the outside of the bow window are to be 10-24 threaded holes spaced 1.312 ± .010 center to center. Minimum thread depth shall be .250. Mounting holes in sights or other side mounting accessories should conform to these dimensions. A line through the axis of the holes shall be parallel to the bowstring.
EXPLANATION: 10-24 threaded holes are used to provide a secure fastening for bow quivers, fishing reels, etc."
Tells you how far apart to place the holes and that they should be parallel to the string. Still doesn't help you determine where to put them on the riser. The 1/4-inch depth is rather shallow and will likely keep folks from drilling through the side of the riser, but i still think it's a good idea to place the holes above the window cutout.
Personally, I've always found it more useful and better looking to cant the bow quiver as well, but that's a personal preference. For an example, if you can find some pictures of Paul Schafer, I believe he used a quickey quiver cant mounted on his Silvertips.
Regardless, now you know the AMO standards. Good luck.