Red Wing 2268's can be dated using their tags and ANSI markings. Just the same, one can determine the approximate age of their non-RW Engineer Boots that possess similar markings.
These nicely resoled Chippewas with #705 Vibram composite half-soles and Quabaug heels are marked PT83, which were made from made from 1983 through 1991. Based on the logo, these would be circa early 1980's.