Yes, the pin is obvious. BUT it is too far forward. All the Classic sights have a pin that holds the front half of the "dovetail" down. When the gun arrives, I'll bet there is a screw in the sight base holding it on the barrel, and an 1/8" hole in the front under the sight.

I scaled the picture, and it looks like the barrel really is close to 7.5" long. I have never seen that length before.