> The only take-apart design I've seen is a 3-piece Romany (fiberglass);
> I've never seen such a critter in wood. But here's an idea:

Nigel Dennis makes his three piece Romanys similarly. They build a standard Romany and install doubled bulkheads, with a saw-kerf-width spacer in between. They drill holes, install bolts, and then have at the boat with a saw. The trad secret seems to be how to guide the saw accurately. You'd have to be brave to do the first one.