Joe Jefferson was the original producer of the session. Clearly, he leased these 2 cuts to Magnum first. I saw the record out on Magnum in spring 1965, at least a year before I ever saw ANY Mutt & Jeff record. Mutt & Jeff was Joe Jefferson's label. I believe he started it up in mid 1966, and re-issued Perry's "Move On Love". The Magnum Monarch pressing code numbers were 56294/5, which indicates mid March, 1965. I believe the Mutt & Jeff issue was released in 1966. I believe that Monarch used the same stampers as were used on the Magnum pressing, and, therefore, used the original code number from the year before.
The MGM issue is Catalog No. 13621, which, I believe, was a 1966 release. That would indicate that Jefferson AGAIN leased Perry's record , this time to a major label (off the sales of its Mutt & Jeff release). I will now check the dating on the MGM 45 releases.