Skwerlhunter,
I have not seen a Universal Enforcer carbine in 30+ years. These were sold as pistols. No buttstock, correct? The one my buddy owned had a normal barrel band. There was a barrel band retaining pin embedded in the stock on the right side and the band had the hole for the retaining pin to enter. There was no bayonet lug and the tightening screw was on the bottom of the band as on later issue US GI carbines.
The Universal carbines are not military spec and were never issued or built for the military. Later versions actually had a stamped op rod with a slot cut into it for the bolt lug to ride in rather than a raceway machined into a thicker metal piece. These were known for cracking. The return springs were two small dual springs also if memory serves me. Thus a military op rod is not an option.
Are they still made? The last manufacturing was in FL I believe. I worked on one for a shooter in our club in the early 1980s. It was not an Enforcer. Universal carbines went through many iterations, form originally being military spec type carbines (pre Enforcer model I believe) in the 1960s (they were sold on the R&S Auto Store gun racks next to the Plainfield carbines, all next to GI versions) to being quite unique designs in the 1970s and 1980s. Hope this all helps. Pehaps Universal altered their Enforcer, but what I describe is what was on my buddy's Enforcer ciirca 1974-5 or so.