I went back to a portion of the messenger contact with the bike owner when inquiring about the bike. I asked if the frame was Reynolds 531. This was her reply:


It’s made of molybdenum or something like that, in 1972 I ordered the frame, motobecane components and sew up tires and rims. Rode many hundreds of miles, wore out all but the beautiful frame. Replaced with high pressure rims and tires and shimano components. I’d be happy to show you.

Anthony

Appears this is a custom frame which explains all the irregularities.