Camp Perry bench dimensions/plans?

Anybody happen to know the dimensions of the green benches we shoot from at Camp Perry?  Just moved into a house that has a home theater and I'm setting it up for dry firing.  Ideally would like to build an exact replica of the benches at Perry but could make it work with just the bench height.

I realize I can make the height whatever I want but would like to get as close to authentic as possible. 

Thanks in advance for any help!

I believe they were only 30" high, although I did not measure them, again!

https://www.bullseyeforum.net/t4902-bench-dimensions-camp-perry

Remember the height depends on how deep the mud is.

- Dave

Thanks guys!  I figure 6' long and 31" high ought to get me close.  I think a pair of 2X10's will work for the top for what I'm trying to accomplish.

Some had plywood tops, some 2x10?

I know a Irwin spring clamp would work on them.