Only on the used market. Check on eBay, and in the back pages of gun periodicals like Shotgun News or Gun List. sales@countrygunsmith.net
Check the parts/service page on the Remington Society of America, see related links.
yes
Remington Model 12 barrels are threaded to the action. Barrels can be replaced with the proper equipment.
Your best source on information would be to contact Remington via their web site.
Does it read "kec" or "ked"? The Remington web site indicates 4 grades of Remington model 1900 double barrel shotguns (http://www.remington.com/library/history/firearm_models/shotguns/model_1900.asp): Grades Offered: K - Remington steel barrelsKE - Remington steel, auto ejectorsKD - 2 stripe Damascus barrelsKED - 2 strip Damascus, auto ejectors
Find an authorized Remington Repair center. You can find a list on Remington's web site.
Try Master Distributers at masterparts.net. The M16SC is a direct replacement. the model# is111174-01 remington / chainsaw/ replacement chain 16" #16SC
Remington, Brownell's, gun shops, gun shows, want ads, e-gunparts.com
Steel or Damascus barrels?
There have never been any recalls on the Remington Model 742 that I'm aware of. The Remington 742 is now an obsolete model and was replaced with the Remington Model 7400. The bolt received an upgraded design along with the magazine catch/release. At one time Remington was offering a Model 7400 as a replacement for the Model 742, if you sent them your Model 742 along with $350.00. Is there a problem with the 742 that you have?
270 is a caliber not a model... For date check the Remington Society of America site for the date barrels codes: http://remingtonsociety.com/rsa/questions/barrelcodes
gun shop, gun show
You will not likely find a Remington stock. I put my 722 in a Bell and Carlson stock and I love it.