Eric,
If i can find a picture, I will post it. The short answer is yes I did cut a hole in 3 sides of the blind and wind-blocker material and left the blind material attached at top. I left the top attached so I could roll it up or down, but mostly I just let it hang down and the dog pokes his head through.
Avery says the blind will fit boats up to 18'. I called avery before I bought the blind and specifically asked if there would be enough material to cover an 18' Lund Alaskan. I was told YES. I then ordered the blind and custom fit it to the Alaskan. When I went to put the wind-blocker on the frame it was obvious that the wind-blocker would not even reach the gunnel. Luckily I had a raintop leftover side, but I had to order a second set of die cut camo and when I told avery that it did not fit the did NOTHING but took my money. I cut the leftover raintop down the middle and sewed it on the bottom of the wind-blocker so that the windblocker would go down to about water level. We then marked the spot for the dog door and cut that in and Velcroed the outside of the 3 sides so the door could be Velcroed closed if wanted.
As for the dog ladder, it is version 4.0 of the original dog ladder that Seark was selling in 1999. I have cut and welded it to suit my needs. The ladder bracket clamps onto any gunnel by design. I modified the ladder to fold out of the boat perpendicular to gunnel. Because the dog ladder has a hinge point where it fold down into the water, it also folds very nicely and quickly back into the boat. The ladder can be folded through the dog door for quick cripple chasing or over the collapsed blind. I will get some pictures posted.
As for the height above gunnel, You can adjust the height by cutting down the legs evenly at the break point. This should be done after the blind is mounted and you would need to cut equal lengths from both sides of the hinge point/break point in the legs. If you wanted to lower the blind 4", you would cut 2" off each end of each leg or the blind will not fold up correctly.
And one last thing. the ball bungees that Avery sends are sharp at the bottom of the ball. This sucks when it is cold and you are trying to wrap up the blind. I bought a bunch of ball bungees and installed extras when I put the blind together. If I had it to do over, I would NOT have used any of the ball bungees that Avery sent. They suck and the other ones I bought are still working great.