Here's a better pic and some measurements:
Measuring from the quarter/dutchman seam the first two holes are 2.1/4" and 6.1/4".
The two holes at the center of the panel are each 1 3/8" from center.
the remaining two holes are centered between the above two groups, but on mine one is dead center, and the other side is about 1 1/2" off center. (the one in the pic is off center)
Hope this helps.
Good luck, Dan