It's difficult choice. Build a hard dinghy or buy an inflatable. Either way storage is an issue. I have no idea hpw the previous owner worked with a 10' rib and 15 hp motor. Skylark had a small fiberglass dinghy that worked well.
Since this is a first try, buiding from inexpensive ply and leftover materials felt like the way to go. So far it is working out. The most difficult part was lofting the parts from 8.5 x 11 drawings.
One goal is to keep the weight down and though the ply is only 5mm thick the resulting structure is suprizingly stiff.
Now we are involved on the fiddley bits that take a lot of time. Bulkheads, seats, gussets, etc. Intructions and patterns for these items are not provided.