Great article! I will offer just one suggestion, that is,
using proportional dividers to take off measurements. You set one end to a known dimension (your Grandfathers height), and the other end to that measurement in the scale you want to build in. Then, whatever you "measure" on the photo with the first end, comes out as scale on the other end.
If the original setup is done precisely, you'll be within +/- 2 scale inches for most of the measurements. Paralax error may have to be adjusted for if the photo is a 3/4 view, where perspective is invloved.
Pete
