Looks like there are still a lot of "mysteries around this recall.
I have a 4" 624 that was manufactured in 1985 and is in the serial number range for the recall (AHB3xxx). I have fired about 200 rounds through it over the last two years with no problems. I do not use hot loads and don't intend to. When I found a 6.5" 624 that I was interested in, I called S&W (my E mails somehow do not get through) and was told that they did not have specific serial numbers, just ranges. He also said that if mine had been fired, it was probably OK! That is not reassuring enough to get me to spend $800.00 on another one, but I plan to keep shooting the one I have.