I looked over these photos and have a few comments. It does look a bit like a later model Pierce but so do a dozen other models of that era. It is hard for me to pin point any unique identifiers. The head tube drilling would suggest that it is a Pierce head badge but many of that era were also not symetrical in bolt/pin pattern. The front fork on my pierce has both drops fully closed. Puting in and taking out front hubs is a real challenge. Also the BB is quite different. If I may ask, how did you remove your crank and BB. Were they one piece. You see mine has a port hole opening on the bottom of the BB shell that is used to somehow unlock the seemingly single piece crank. I have not yet figured out how this is done. You cannot remove the crank from my machine from the outside of the BB. I may take a few photos of my frame and fork and send it on for comparison.