The sketches were found alongside some writing, all in perfect condition in a sealed shopping bag.
2nd Lt Whittles, from Altrincham, described the waist-deep mud conditions in the trenches at La Boisselle as vile.
He was shot in the arm in April 1918 and evacuated to London for surgery.
2nd Lt Whittles remained as an army officer training young soldiers in Warwickshire before serving in The Rhine area of Germany until Autumn 1919.
He returned to Withington, South Manchester, became a civil servant and married Lillian.
The couple had two children, Graham and Margaret, David Burrows’ mother.
Graham Whittles died in service on patrol in Amfreville in World War Two in 1944.
Heartbroken, his father died later that year aged 54.
