Not a lot of information out there on dates of manufacture for DWs. Values will depend on exact model, barrel, etc. Typically $200-$325. IMHO, they are the most underappreciated revolver around- they are durable reliable, accurate, and built like a tank. Great guns.
Check on the butt.
Impossible to answer without the serial number.
Feb.1984 with the serial number that you have provided.
25-450 usd
100-450 or so
100-500 usd
@1984
100-400 USD
100-400
1956-1957
250-500 USD
1974