Heavy rowing boat

I have a 10ftX5ft fibreglass rowing boat,rows really well and goes great with an 6hp Evinrude
on it.
It's an old boat and has seen a few repairs and amateur jobs done on it.
My problem is,it's very heavy,much more than you would expect from a f/glass boat this size
It has an external 2" Gunnel (on the outside)
I drilled the gunnel in a couple of places and it is sodden timber.
A previous owner has put a forward central and rear seat setup in it and has attempted to
use them as flotation chambers.I removed part of the central seat,and he has used
3"X2" timber and squirt in foam,all the lot is soaking wet through.I suspect the front and rear seats are the same.
I intend to remove the lot and replace it with single plank seats.
I am contemplating cutting the gunnel at the outside corners and removing the timber,and replacing it with 2"X2" square plastic downspout and fibreglassing over it.
Where the rowlocks go,I will use some decent timber to give it added strength.
The keel is "U" shaped and is visible in the bottom of the boat,so there is no timber in it.
The last bit of the keel at the stern is a box shape and is hollow and sealed.(I drilled it to check)
I suspect the wet soggy timber and foam is adding the excess weight (probably about 100lbs)
The boat is very stable on the water and does about 8mph with the outboard on it.
The transom has been constructed from layers of ply and is so thick I have a job fitting the outboard clamps over it.I suspect that is wet through also.I will probably replace it with a 3/4" piece of GRP glassed in.
I have no pics available at the moment,it's sheeted up.

 

Your plan sounds good to me. Post progress pictorially.

 

Hi H,
Will do. Glad you approve of the plan.
The boat is outside,just waiting for the weather.

 

Merry Christmas.

 

And the same to you my mate.
Sounds like your new president could turn out to be your Santa Claus