Yes
600-1200
500-800 depending on what "very good" turns out to be.
100-1500 US dollars.
Very poor description to base a value on. Broad range 300-800 USD.
No way to answer without the entire serial number. You can call Colt and they will tell you.
To determine the age of a Colt AR-15 A2 HBAR Sporter with the serial number SP221219, you would typically need to consult Colt's production records or a firearms expert. However, Colt generally produced the Sporter model in the late 1980s to early 1990s. Based on the serial number, it's likely that this particular rifle was manufactured in the late 1980s.
Model 6601
You will have to call Colt to find out.
100-1000 usd
Fiind a copy of "The Black Rifle", both volumes. You can research it then.
Any of the on line auction sites, gun shop, gun show, Shotgun News.
I just purchased one from a dealer in like new condition for $1,000. I believe that to be the low end of the value of this gun. Most in this condition will be higher.