We recently purchase an older (Montgomery Ward) riding mower and would like to find a users or owners manual. I've looked in the usually sites on line. The engine is Briggs and Stratton, Model 289707, Type 0151-01, Code 9103104B. Seller was not original owner, so doesn't know the age.
The engine code tells the date that it was manufactured.
910310 translates to 1991 / 03 is March / 10 is the date
March 10, 1991 The mower was most likely manufactured close to that same time.