Plimpton 322 Mystery Cache

Much in our common systems of measurement today has its roots in Babylonian mathematics. The influence of ancient Babylon is still evident in our methods of measuring time and angles (i.e., there are 60 seconds in a minute, 60 minutes in an hour or degree).

This puzzle cache, which is going to require more brain power than brawn, has two locations to visit. The first stage is somewhere in N41 23.XXX W74 42.XXX (you'll need to determine the decimal portion of the minutes). Once you find it, your brain work isn't done. The final is found somewhere in N41 22.XXX W74 41.XXX, not far from the posted coordinates.

So here's your chance to be an archaeologist. The first row of this chart is complete but there are missing entries in the second and third rows. Decipher its meaning, find the missing entries which will complete the coordinates for stage one, and off you go! An appropriate FTF prize awaits first finder! (For obvious reasons, please resist the temptation to post photos of the sites in your logs!)

You can check your answers for this puzzle on Geochecker.com.