I changed the rear fixed sight on my 1992 MK-II standard to adjustable sight but it won't work in combination with the original front sight because I'm hitting to high on the target. I did all the up's & down adjustments on the rear sight but still hits high. I think the front sight is to low to be used with a adjustable rear sight. Can the front sight be changed or replaced with a different style or higher sight on this particular model? Here's a picture of the front sight on my 1992 standard MK-II.