If secondhand - or even new! - Optimist parts are used, all that remains is to make deck from single sheet of plywood and provide mounting points for rudder and centreboard.
Deck is screwed together from four pieces: 2 side boards, bow and stern. This is done in such way, that boat is actually longer than original plywood. It also allows to disassemble the deck for easier transport.
Not much experience is needed to make necessary parts and hardly any tools (power jigsaw and disc sander help but are not necessary).
No part is longer than 8 ft or wider than about 2.5 ft. It should be possible to transport the lot on roofrack. To assemble booat on beach the deck is assembled and lashed or locked into inflatables's handles. Then centreboard is mounted in lifted (horizontal) position and mast is inserted in its bracket.
Advantage of "Optimist" rig is that if boat is overpressed by wind all what is needed is to let go of the sheet and sail with spars will weathercock. Works like putting gearstick into neutral in car...