The conventional wisdom is that there are four date wheel types observed on the 1675. While it is nice to have a period correct part, an incorrect date wheel is not thought to be as important as the aesthetic difference is so minor. It is up to you how important having this ‘correct’ is when assessing a piece. Here is the general progression of the date wheels based on year and distinguishing characteristics:
- Early 1960’s to Middle 1960’s: round 3, closed 6 & 9, and flat 7
- Middle 1960’s to Late 1960’s: round 3, closed 6 & 9, and hooked 7
- Early/Mid 1970’s: flat 3 and open 6 & 9
- Mid/Late 1970’s to Early 1980’s: round 3, open 6 & 9, silver brushed
Pictures Forthcoming