The shape and size of the brushed 'sides' are distinctly different. The later (current) cases have a brushed area that is slimmer and tapers towards the ends. My '68 'Transitional' (never polished) has significantly taller brushed sides that curve down abruptly at the ends. From my observations the '68 case style extends to '69, but the majority of '71 are different. Oddly enough, I have found it easier to fit 633 end links on my '68 than on a '71, because on the later case the inner curved (brushed) part of the lug extends down to the springbar hole, so the 633 sits up much too high and leaves a gap. The older flat link bracelets fit these more neatly.
Click to expand...