Have you called S&W and talked to a customer rep or a tech about this? I take it that these were manufactured around the year 2000 from the thread title, right? If so, they are supposed to warranty for life on material breakage. Other than that, I can't help you on this as I have no top break experience.

PS, you also might try PM'ing a moderator and have him move this over to the Gunsmithing forum, as you might get answers on this problem there more quickly.