This model came in a few different calibers. 1966-1979 so far is what I have found for dates. 22" barrel, Walnut stock. Blind feed magazine. The 670A was noted as a cheaper version of the 670.
not sure if this link will work for you as you have to make an account on Gun broker to see completed auctions.
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=161116123
Chat with our AI personalities