I have built a little card model of the Portuguese dinghy to get a better feel for it. The cross bulkheads are only there to hold the model shape, they are not there in the finished boat.
Quite different from the Peanut pram. Significantly smaller and with a flat bottom. I have a feeling I may end up building both for the fun of it. The dinghy is the simplest as it only requires straight saw cuts and the flat bottom means far fewer joints to form and fill. I am planning to add a skeg or even a full length shallow keel to to keep it straight in the water, and possibly a couple of wheels for trundling to the water's edge.