In beginning this thread I should have mentioned that my experience with getting through via phone calls to customer service at S&W and now T/C, as well, is rather poor. It takes a LONG time on hold.
I did, in fact, call this past week after their holiday shutdown. After waiting on hold for 27 minutes, I was advised by a seemingly indifferent representative to return at my expense the rear sight with the flat bottom for an exchange.
While I don't particularly mind returning the sight at my expense, the reality is that this issue is nowhere logged into their system. Had they issued a prepaid mailer, there'd be a case number or some sort of identifier. Whether I ever hear from them again remains to be seen.