This is a near-definitive modeling reference, for not only plank on frame but techniques that apply to all modeling methods. He tells how to find the shape of the frames from the lines on plans; he includes tables on the real-life thicknesses of every sort of rigging line if one wishes to replace the inaccurate thread given in kits; he tells how to apply apply the coppering and also what size the copper plates made in, so one may make properly-scaled plates of one's own; and he describes which woods to use for what and how to make blocks, dead eyes, and even chain link from scratch. Every couple pages is a page of photos or sketches that are infinitely helpful. I am a member of a ship-modeling email newsgroup, and when I put a query about scratch building, there were dozens of reccommendations for books, and the one book everyone suggested was Harold Underhill's Plank on Frame Models and Scale Masting and Rigging (which is why I purchased it), even refering to it as the "bible" for plank on frame modeling.
   His books are restricted to merchant and non-war ships, so unfortunately there is nothing about cannons or any unique men-of-war construction techniques, and he doesn't explain how to cast one's own metal fittings or how to photo-etch. Perhaps, I am only guessing, as this book was written in 1960, such techniques were not available at the time.