Hey Lawrence, I think it might be worth your while to not only draw the sails, but to also check the proportions especially of both mainsail and the main gaffsail. When I drew up the sails, I couldn't help but think the proportions weren't right when comparing my plan with the Model Shipways drawings.
Currently these are my preliminary findings:
1) the main boom dimensions appears to be rather spot on.
2) the main gaff appears to be too long, around 20mm, 0,8".
3) this causes the angle of the upper edge of the main gaffsail to be shallow.
Right now I'll have to amend my sail plan and check whether correcting the main gaff results in an esthetically more pleasing gaff sail. Before trying to even touch the Admiral's sowing machine, I will first have the booms and gaffs in position, cut some paper sail, based on my sail plan, and check the fit of the dummy sails. Only once satisfied with the dry fit of the sail will I continue to produce a real set of sails.
Below the sketch of the sail plan, second draft.
Next will be to update the main gaff length and adjusting the main gaffsail.
Dimensions: