[deuce560]

WT barrel code indicates manufactured in August 1970 or August 1999. the date KW code would be May of 1972 or 2002. If it's WZ that would indicate August of 1975 or 2005. The "L" prefix on the serial numbers was used between 1968-1973. My best guess would be they are both early 1970's guns. You're probably aware that these barrels can be readily changed around so date codes on barrels of these guns that have been around may not match up to the rest of the gun.

For current value I'd advise going on gunbroker.com and looking at recently completed sells. Jack is correct that they are likely worth more in parts now since Remington post-bankruptcy isn't currently making any replacement parts.