Just a quick update, in post #25, you can see 2 sets of "trolleys" bolted to the hinge. These keep the seat aligned and allow it to slide out, prior to lifting up. Sounds more complicated than it is. Lifting normally, on the handle lets it happen in one fluid motion. I had some time to make some adjustments recently. I moved the lower trolleys about an inch further up the hinge by drilling new holes in it. This allows the seat to be opened further without those trolleys coming out of the track, which happened a few times. My temporary fix, was a bungee keeping tension on the track to keep the trolley in it. With the newest adjustment, it is very smooth and functional. I wish I did it last year, but never took any more time to work on it. I doubt anyone is going to do this mod, because cutting a perfectly good seat is risky, but just know, it can be done and work well!
If anyone wants to build a refined version, I suggest using lower profile, flat drawer sliders from Home Depot or Lowes. If I ever get the time and motivation, that would be my next plan. A fully functioning kit, with detailed instructions and a seat cut template would be awesome, but due to variances in these boats/seats, not sure its possible.