Whaaa???? Mine has 73 stamped on the seat tube/top tube lug. How can this be? If this is to be trusted, no one came close in dating this bike - there has been near total unanimity in putting it at 82'-83'. It was a twelve speed and did not have cottered cranks when I got it and though not a lightweight, It was a hair over 26 lbs before I slimmed it down to 24.3. (lighter at the start than my first mirage of late 70's vintage -don't ask me anything about this, I just don't remember but for the simplex derailleurs and centerpull brakes.) This is getting interesting.

I'll post pic's later.