I've been looking for something like this since I started putting together my game plan for this season, which will have three main pillars, one of which is kite fishing Florida-style ie. a 3-rod holder stand. It will be used for two rods and a kite rod in the middle. This contraption will be placed midship, fishing two live baits down wind and two other rods will be drifting baits on flat lines on the other side of the boat.
This will also be useful for storing rods out of the way on those busy light-tackle days.
I "canibalized" two old trolling boards from Oba Oba the Kei Marine that belonged to a friend. One, I'm turning it into the footrest of my fighting chair and the second I used in this project.
The plastic rod holders were leftovers from maguro and as you guys know I can't just ignore a good opportunity to recycle and reuse "trash".

So here is the progress I've made thus far...
Drawn the pattern into two A4 pieces of paper stapled together, and used a small Black & Decker electric saw to cut the section. I drilled the holes and voila.
The pics are pretty self explanatory. What's left to do is fill a few holes with fiberglass "pap", sand and give it a coat of red.
The footrest that will fit into the boat's gunnel rod holder will be made out of a hard wood. My dad his turning a square piece of wood into a 37 mm round rod, as I don't have the tools.
Will keep updating as the work progresses...