Sure its pretty straight forward really first think I did was get some 1x3 board pine and some 1x2 board pine, I cut two pieces of the 1x3 at 22' and one pieces at 14 3/4 , then I took the 1x2 and cut two piece at 14 3/4 ,and two pieces at 19'', I took the one by three and made the back and the two long sides, and used a 1x2 for the other end, the one by two I set on a 3/4 piece to keep it at the right height for a entrance reducer. infact that is what I used to hold it up, an old reducer on hand, then I glued and nailed it together keeping it as square as possible. I then took the three remaining pieces of 1x2 and ran it around the inside of the 1x3 frame, nailed and glued it in place. then just stapled the #8 HWC in place, trimmed it and done.
One thing I did on the second one was that I changed the lay of the 1x2 so that it was edge way back on the front sorta like a short landing board. the one in the picture goes up down, the new went front to back, reversed the two pieces actually (see picture) thats all there is too it. :)
Can you provide instructions on what you did? I may attempt this myself.