Well Bob Hovey and Brian will probably know for sure, but it looks to me as if the stamp on the right side of the M cutout is +GF which is the mark of the bottom bracket maker Georg Fischer. The numbers to the left of the M cut out appear to be 617 (read upside down). So this could be CaliMasi #617. If so it's a 74 or 75 and not a 1973 as claimed. Note also that it does not have a twin plate fork crown, which would have pegged it as a 73. Instead it's a non-slotted Fischer fork crown which indicates 74 75 or 76. Additionally, the lugs are pressed and not investment cast. All this seems to indicate an early 75 GC to me.
Steve Shaw Millbury, MA
-----Original Message----- From: David Bean <beandk@rcn.com> To: CR List (E-mail) <classicrendezvous@bikelist.org> Sent: Fri, 7 Dec 2007 11:12 pm Subject: [CR]Ebay Masi
Item 170175732352 Can someone interpret the stamping on the BB of this bike?
David Bean
Arlington, MA
beandk at are-see-enn dot com