Since your question was whether American pistols were made with the rear sight mounted back at the tang area I looked through one of my Kentucky pistol books.
Of 76 pistols shown, 55 had either no sights at all or just a front sight.
21 had front and rear sights, with the rear sight placed out on the back half of the barrel.
None had a rear sight mounted back around the tang area.
That's not to say that it was never done, but if it was, it must not have been very often.
But if I was going to build a target pistol, I'd spread the sights as far as possible!
John