Here are pics.
Here is a pic with the tape next to the driver's seat. You might note that the raised areas stop where the seats mount.
http://i221.photobucket.com/albums/dd45/HomeCrafter/IMGP2193.jpgHere is the passenger side. You can just make out the hole 5/8" from the edge, and at about 14 1/2". I THINK these are the factory holes, as they are much "nicer" than the others on my truck, and don't SEEM to be drilled at home.
http://i221.photobucket.com/albums/dd45/HomeCrafter/IMGP2195.jpgAnd here is how I mounted the passenger (which is another driver's) seat.
http://i221.photobucket.com/albums/dd45/HomeCrafter/IMGP2198.jpghttp://i221.photobucket.com/albums/dd45/HomeCrafter/IMGP2196.jpgAs you can see, my truck is quite grubby apparently. Darn mud. I cut the bottom of the seat bracket off, and used a yoke as a hinge. I still need to get a shorter yoke, as the seat sits too-high. I also need to turn the rear blocks round, I never bothered to, as I knew I'd be making shorter ones anyway.
Now, I used two driver's seats, that came out of one other truck! In fact, I even bought the seats at different times, from different owners of the same truck! My panel didn't come with any seats. The passenger seat mounting holes should be located in the same way as the drivers, (I think) inboard passenger holes would be located where the raised areas are interrupted.