Archie - I would say that would be true, most of the early strikes with .999 on the rim seem to be .595 oz to .605 oz.(but dealers are not wanting to buy those centers at the present I find unless they can buy them for $4 to $7 behind spot) The ones with .999 on the center seem to be more likely to be less than .600 oz and the average is .590 oz.
At least thats what I have found in the 600 or so that I have weighed in the last month.
Walt