The photograph of Michael Blake's eighth birthday is dated 1928. However, the date of birth on his tombstone is July 14, 1922.
When the Rolls Royce pulls out on to the street right before Sam shows Mr. Blake the box with pictures there are clearly 70's and 80's American automobiles on the street, cars that didn't exist in 1962.
The stereo receiver in Michael Blake's office is a Kenwood TK140X which is solid state and was not introduced until 1968. All audio equipment and receivers in 1962 were still using tubes.