In the early hours of May 28, while recording 'Blue River', the last song of the session, it was announced as "0307" by the recording engineer while recording. However, unbeknown to the engineer, that matrix number had already been assigned to Jeanne Pruett for her song 'Little Black Book'.
It seems RCA did not realise this mistake until 1965 when 'Blue River' was scheduled for release, and was assigned an new matrix number - SPA4 6768. It is interesting to note that the SPA4 6768 matrix number releates to the unedited Take 2 of 'Blue River' which was not released at the time!
In order to make 'Blue River' longer when originally released as a single it was spliced from 0:00-1:25 and 0:44-1:31 of Take 2, and this was issued yet another new matrix number, SPA4 7357, in 1965. It was this spliced version which was released as a single (47-8740) in 1965, and later on the Double Trouble album in 1967.