Middle Seat Bracket

My short story.
I have fished my whole life from the beach.  As a teenager I was introduced to fishing from a "Crocker Ski" in Amanzimtoti, an experience which has never left me.  Life goes on, as it does, and only recently did I decide to start fishing again.  I decided to get myself a yak to fish off.  Problem was that I now had 2 sons (11 and 10) and purchasing the Stealth BFS (My dream fishing ski) just seemed too difficult to get past the missus.  ;)
A mate of mine has a Wilderness System Tarpon 130T (Tandem with the middle seat for when you are on your own)  Perfect!  Only problem is is that the really comfortable back rest only fits on the back/front seat positions and there is no backrest for the middle seat.  (Were I will be spending most of my yak-time in).  My mate has a hammock like middle seat which I tried but did not find comfortable at all, as every time I twisted to reach behind me to get at a milk-create  the fabric seat would shift and I would battle to get it into the correct position again.
I decided to build a bracket so I could take the backrest off the rear seat and move it to the forward position (middle seat)  I have NO experience with fiberglass but found all I needed to know on the web.  Just so you know the level of craftsmanship I am a software developer, mechanically challenged, but love to tinker with stuff.

Were the backrest normally goes.

Were I would like to put the backrest.

This is what I came up with.  Still some work to be done here...  smooth out the whole thing with body filler and sand sand sand etc...

A view from behind... so I can still use the hatch...

How it will all connect together.

I should have gone with the double think milkshake... so more sanding this evening...
I still need to finish off the bracket which should be happening this afternoon.
I do have a question though.  How am I going to attach it to the yak?  I have thought of putting some nuts and bolts through the yak.. drill some smaller holes and then screw and silicon the bolts in place then attach the bracket in place with more sillicon and the nuts...  Any suggestions?
So I sanded the milkshake almost all off... I didn't put enough catalyst in so I could scrap it off... grrrrrrr
Any way... after a load of sanding and a bit of spray paint  you get a VERY DARTH VADER seat bracket... :lol:  
A few more coats and a bit of sanding and I'm good to start drilling for the fixing nuts.

All that's left to do is fix it to the yak.

Pardon the REALLY dusty yak.. proof of all the sanding that was done.

6 little bolts fastened from inside the hatch and we're away...
Gotta get this baby into the water to get rid of all the dust.  Can't Wait