1991 Chaparral 2000 sl stringers

I have acquired a boat,long story short. It had problems with the deck having rotten wood. The deck was torn out and the stringers removed. The foam and all the insides are now off to the side.

We have winterized the engine and want to try to put the boat back together. Only deal is, we don't know what it looked like before the destruction. We don't have any pictures of the stringers, and have looked online for some type of a templates. There don't seem to be any. I need to know how long to make them, how to arrange them and if there is a recommended product that I should use to replace the stringers.

The boat is 20 ft long.