Most of them seem to be NBPEL. The one I can think of off the top of my head that was BPEL is the German one - Schneider. Wessels was NBPEL, but they also measured each guy's fat pad. One of the Middle Eastern ones(either Jordan or Iran) was bone pressed, but they measured flaccid, stretched length.
I personally think the Ansell's Lifestyles(Cancun) study was NBPEL, but they never published their methodology. That's an email that I would like to write, but I've been too lazy. I'm not sure you'd get a correct answer anyway, because you'd never know who was answering you, and how hard they tried to get the correct answer.
I'm pretty sure the instructions for the Kinsey study were to do an NBPEL measurement, but based on the results, I think a significant number of guys cheated at least a little bit.
I'm curious about whether the French study(Bondil) was NBPEL or BPEL. They measured stretched, not erect, and the mean was crazy high.