Just built a new one for my TJ. Using a 1x6 I cut it to fit between the rollbar under the sunvisors. I cut a small 3/4" strip of 1x and mounted it to the back edge of the board to form a lip to keep things from sliding off. Glued foam on it, and wrapped it in vehicle carpet.(Leave foam & Carpet Long on the ends, to cover metal mounting bracket) Then made a 2 metal brackets using a small piece of muffler pipe cut in 1/2 to form over the top of the roll bar, and welded a L shaped bracket to that to hold the edge of the board. Once in position hanging on the rollbar, I drilled through the existing soft top door frame hole in the rollbar, through the muffler pipe, and bolted it to the rollbar. Added two nylon straps with quick relase buckles to hold rifle in place, an wal La, instant gun rack. (Best part, with the hard top you can't even tell there is a gun in the rig.)  

Cool, can ya post a pic or two of it.  

97scramln:
Just built a new one for my TJ. Using a 1x6 I cut it to fit between the rollbar under the sunvisors. I cut a small 3/4" strip of 1x and mounted it to the back edge of the board to form a lip to keep things from sliding off. Glued foam on it, and wrapped it in vehicle carpet.(Leave foam & Carpet Long on the ends, to cover metal mounting bracket) Then made a 2 metal brackets using a small piece of muffler pipe cut in 1/2 to form over the top of the roll bar, and welded a L shaped bracket to that to hold the edge of the board. Once in position hanging on the rollbar, I drilled through the existing soft top door frame hole in the rollbar, through the muffler pipe, and bolted it to the rollbar. Added two nylon straps with quick relase buckles to hold rifle in place, an wal La, instant gun rack. (Best part, with the hard top you can't even tell there is a gun in the rig.)

And for the people who don't have the time, material or know-how to build one you can buy this one.  Basically the same concept just more expensive.  For the record I like yours better.

http://www.quadratec.com/products/14139_002.htm