Rupert, you are obviously comfortable with your methods, which seem to involve a lot of 'eyeballing' of dimensions. Obviously, it works, for the most part, and your existing models prove that.
However, I do wonder if much of the angst of getting proportions and dimensions correct would be removed if you had acess to 'authoritative' plans. Have you ever tried contacting the folks that manage and run these buildings to see if such plans exist? Yes, the buildings you create are all very, very old, and plans
may no longer exist, or there may only be relatively basic ones available. But you mmight be able to get the
fundamental dimensions pinned down quite accurately, form which much of your 'eyeballing' would surely be easier? Just a thought.
I guess I am the type of person who just
wouldn't have the courage to undertake the beautiful modelling that you do without
way more in the way of good measurements, angles, profiles etc as a starting point. I suppose I just don't have the artistic flair to do this sort of thing, heh heh!