And let's talk Colt weirdness.
Here's the Blue Label R6601 I bought in June 1990. I ordered the rifle just as soon as Colt made them available again. At the time I was working in a sporting goods store and we got two HBARs in. I got to choose which one I wanted, though I believe they were marked the same. The owner's buddy got the other one and I don't recall who he was so there's no way I can track that rifle down. It sure would be interesting to see.
The receiver is your standard SP1 type slabside lower in all aspects and features.
I've know for several years this is a rather unique rifle. It has all the A2 features and furniture but is built on the SP1type lower. In fact, I've seen pics of more than a few AR15A2 marked rifles with higher serial numbers (SP range) than my obviously later built and marked rifle. This leads me to believe that Colt makes/made runs of receivers and stamp only the serial number on them at the time of manufactor. Then add the model and other rollmarks when it finally assembles the rifles. Thus my lower numbered receiver went into a bin first and was pulled out and asssembled after earlier models with higher serial numbers.
So let's see yours and talk and compare Colt weirdness.