So it only makes sense to start with some idea of the dimensions you intend to use when building a model. That said, I forged ahead and did it any way.
First I took an existing picture of Jpseph Pujol, used the GIMP (Photoshop? I don’t need no stinkin’ Photoshop!) to scale it and print it out to the approximate 12″ tall image I had in mind for the model. I then took some measurements, made some approximations and ended up with this:

I knew it wouldn’t be quite right so I matched up the proportions with the proportions reported for Leonardo’s Vitruvian Man. Needless to say, they were close but not close enough even for a “looks about right” kinda guy like me. So I went down the internet rabbit whole of human proportions and came up with this great image.

I decided some wireframes were in order so I got out the CAD software piano wire and made a couple.

On the right, proportions based on the Cesariano version of the Vitruvian Man
I’m going with the one on the right. The one on the left has too-long arms. The one on the right feels best as a “skeleton” to build the body on.
Next up, a paper mock-up of a body part or two. That entry should be up in a week or less.