Here are some quick measurements I did of mine that's mounted on my Playseat:
Length - 13 7/8"
Width - Bottom rail = 1 3/8", Top rail = 1 1/2 "
Two holes on bottom rail at each end (one on each end is elongated) - located 1/2" and 3/4 " from end
Two holes on top rail at each end (one on each end is elongated) - located 1/2" and 1' from end
It should be possible to drill new holes in the top or bottom rail where ever you need them.