Dave. I like those rifles. And those original buckhorn sights take some getting use to. I found that if you treat the rear sight (the buckhorn) like a peep and center the top of the front sight you might hit dead center.
I was having the same problem with my GPH. I tried to sight with the top of the front blade on top of that little notch in the rear.
But anyway you do it, I'm sure you will get that baby shooting good.