Does anyone know how to "read" Peugeot frame reference numbers? I'm trying to find information about an unusual looking Peugeot frame with a gently curviing down tube. The frame reference number is Y90178024 and the number 72 is stamped on the drop-outs. I can't find anything similar in old Peugeot catalogues. It's a TYP ("Technology Yoke Power"??) frame. Can anyone decipher when this was made and what model it is? Thanks.