This Colt M1911A1 was shipped on March 5th, 1942 to the Commanding General at Springfield Armory in a 1,440 gun shipment.
This M1911A1 still has the rounded front sight. The front and rear sights would eventually change in March of 1943 at about serial number 893000 to a wide and tapered front sight as well as a square notch rear sight.
The inspector stamp of W.B. is for Colonel Waldemar S. Broberg. He was the Army Inspector of Ordnance from July 1st, 1941 to June 16th, 1942 in the Hartford/Springfield Ordnance District.