How ya doin. Never used coosa but the procedure would be the same.
2 layer over transom
2-3 tabbings , each beingf @ 3" wider than the other. So 6" wide first gives 3" overlay, next 6" wider. etc. ea. time covering @ 3" more either side.
I simply ran my glass for the transom 3" wide to tie to floor and sides. Then did tabbing. This is structurally one of the most imp. parts of the boat.
Everyone has a different spin on it.
You will also want to notch out the transom on the bottom where the drain goes and fill with pb now before glassing. Alot easier. This allows you to keep the transom wood being exposed later when you want to cut in your bilge drain.