Need Help with my new starcraft capri 17'

[1974CapriWith88spl]

Just got an old old starcraft 1974 with no interior although its got a beautiful exterior n motor 88 spl jhonson i knew nothing going into this project and still feel i need more info i learn more and more every day i got the engine to work got a gas tank battrey etc i ripped up the floors and the fiberglasing of the stringers is really bad the origanal stringers are rotted and poorly glassed and then instead of new stringers he just screwed new ones to the old rotted ones i need to know if foaming the boat would make this ok and study or if i have to redo tht to. if anyone has any info on a starcraft 1974 like the cover im missing and how to get my fish finder to work and how to work the gas and gears i know the basics but i need specifics for this boat