Seems that the original knobs for 60's Precisions were lighter, .4 once, and the new as well as newer aged ones are heavier at .6 once. First, is that true? If it is, when did the change occur? I ask because when I first heard that, I checked my 60's Precision against a newer one, and there is a noticeable weight difference. Looking for confirmation of just what the truth is. Many thanks.