Quite impressive what you achieved by scratch build this model without good plans.
I think that its possible to ask for plans at the "Museu da Marinha" but should not be easy task to do.
Its good to see paper models from Portuguese subjects as they are so rare, and we have so many good subjects.
Info of the model on display:
https://museudigital.marinha.pt/pesq...x?t=o&id=13804