Remingtons are typically dated from a 2 or 3 LETTER code on the barrel. See the Remington Collector's Association website for the chart.
The address of the Twin Bridges Museum is: Po Box 952, Lyle, WA 98635-0021
Some zip codes in Washington state include 98101 (Seattle), 98052 (Bellevue), 99201 (Spokane), and 98660 (Vancouver). There are many zip codes in Washington state, each corresponding to different cities and areas.