The review of this single in Billboard (17/8/63) has 'That Sunday, That Summer' as the A side. It entered the Hot 100 on August 31st at #97 eventually climbing up to #12 on November 2nd 1963. 'Mr. Wishing Well' also entered the Hot 100 on September 14th at #99 struggling up to #92 three weeks later then dropping out of the chart.
Paul Pelletier's UK Capitol discography list's the UK equivalent on CL 15316 as also having 'That Sunday, That Summer' as the A side.