That's quite the collection. How'd you get the C8 as i thought that Colt Canada (Diemaco) only sold the SA 15.7, SA 20, and Diemaco IUR to civilians.
Your Colt SP1 is also my dream rifle but i'd prefer one with the black furniture. I wonder if anyone here has a Colt AR15A2 or SP2 HBAR.
The C8s were sold as Law Enforcement surplus "parts" about 8 or 9 years ago. I got the Upper Receiver from Nordic Marksman in brand new, unissued/unfired (outside of the factory proof rounds), condition. I added an SA 15.7 Lower Receiver and appropriate Diemaco/Colt Canada period furniture to correctly complete the basic C8, identical to the one that I carried in Afghanistan back in 2002.