I would just check to see how extensive the delam/rot might be. If it is not too bad just butt block,patch and match as needed. There is no mystery to these ply hulls, just simple wood work.
Avoid glassing over the whole hull, just adds weight you don't need.
Check frames and stringers for rot,these might give you more trouble than a rotten ply hull.
If fresh water has been getting into it over the years that can be the real killer....
Done this on a few boats and never regretted it.
The important thing is to get it on the water quickly and have fun, don't make it your lifes work, either it can be saved or not.
And it will teach you something about sailboat design so you know what you like or don't like about that hull style.
Never turn down a free sail rig that is in good shape, just strip the hull of hardware and burn the hull if needed.