I suggest you get ahold of Colt on the phone or online. Either way you should be able to get an owner's manual. You could also go to your nearest gun shop/gunsmith and ask for help. In any event, ask for help if you are inexperienced. We all started out that way, regardless of whether it's with a Colt 45 or a car.
You will have to call Colt to find out.
The .45 Colt Mark IV Series 70 with serial number 66853B70 was manufactured in 1977. The Series 70 Colt 1911 pistols were produced from 1970 to 1983, and this specific serial number indicates its production year within that range.
You need to call Colt. That sn is beyond the published lists.
proofhouse.com
1980-1983
it is disassembled the same way as a military 45 pistol..................
The Colt Mark IV Series 80 in .45 Colt was introduced in 1983 as part of Colt's series of semi-automatic pistols. The Series 80 incorporated a firing pin safety mechanism, enhancing the safety of the firearm. Production continued throughout the 1980s and into the 1990s, with various models and configurations available during that time. Specific manufacturing dates can vary based on the model and production runs.
100-1000 depending on specifics
yes
Published data doesn't cover your sn. You will have to call Colt.
You must call Colt. 50-500 USD
50-500 USD. You must call Colt