I found an Olympic Arms MFR in North Carolina via the Internet at the right price and after verifying its pre-1994 ban status bought it. Firearms maybe purchased though the mail as long as the rifle is shipped between federally licensed gun dealers. The buyer then goes though the Brady Bill restriction check with the local dealer before being allowed to pick up their gun. This photo is of the original setup with an A1 upper with 20 barrel. Im using this upper with a Bushmaster M-4 barrel for the DPMS lower project in a previous page.

Ive replaced the original upper with a Bushmaster M-4 flattop with a 14.5 barrel and a pinned and welded Phantom flash suppresser. The overall barrel lenght is therefore over the 16 limit. The shoulder stock was replaced with a Bushmaster M-4 collapsible one and the pistol grip was replaced with an Ergo grip. For sights I went with an Aimpoint Comp ML in an Aimpoint Rail Grabber mount which features a torque limiting knob. The knob helps ensure that the sight repeats zero after replacement. The sturdy rear sight is a DPMS detachable rear sight.
This combination of sights and mounts places the red dot from the Comp ML right at the top of the fixed front sight. Cheek weld and eye placement is as with my other AR-15 rifles. It is possible to look over the rear sight with both eyes open and use the red dot. Lower your eye an inch and the iron sights are ready. Ive been using the large rear aperture and have been looking though the iron sights with both eyes open. This allows for very fast targeting and keeps both eyes open for awareness.

M-4 Carbine

Before

After

Olympic Arms Pre-ban orginal configuration
Olympic Arms Pre-ban MFR