Thanks everyone for your inputs. I'll be on the hunt! If anyone knows of a "deal" on this pistol, I'd sure appreciate a heads-up.
presspics is right. Smith did make the 5906 Tactical pistol with an "earless" adjustable sight variant. I don't think this version was ever very popular; at least, after years of looking, I've never seen one in the flesh.
Only An Armed People Can Ever Be Truly Free ;
Only An Unarmed People Can Ever Be Enslaved Aristotle