Yes! You can have an ordinary rifle and you don't have to have a license. But a Full-Automatic, military issued rifle needs to have a license. MAKE SURE YOU HAVE A LICENSE FOR IT!
According to info available on ar15.com, your weapon was manufactured in either late 1972 or early 1973. I own one made in 1974.
Try AR15.com Try AR15.com
If it is one of the recent Colt .22LR AR15 rifles, then the answer is no - they are completely different internally.
1959
Yes
The US Army presently uses the M4 carbine, a shorter and much modified version of the Armalite AR15.
Colt has not offered a AR15 in 308
Someone over at AR15.com would probably be able to point you in the right direction.
Yes. Have fun paying for it then lugging it around, though - that's a whole lot of weight you're adding to the rifle.
You must be 18 years of age to purchase a shotgun or rifle,and you must be 21 years of age to purchase a handgun.
By it's serial number. Go to www.proofhouse.com and under 'long rifles' listing look for AR15 Sporter
Depends on where you are. In the US, it is possible for a private citizen to legally own a fully automatic firearm in most states. The transfer of such as gun to you must be approved by your Chief of Police, and you will need to supply fingerprints and photos to the BATFE (and a $200 tax) and undergo a background investigation. You will also need a large wallet to hold the money to pay for that AR15. A LEGAL, registered AR15 sells for about $25,000 today.