The image above was sent to me by Alan Mansfield. here is what he wrote:
“Greg Russo in his book ‘Cosmik Debris’ gives the release date for ‘Deseri’ as 12/30/68. If this is correct then the date stamp of ‘Jan 4 1969’ is just five days later, which suggests that it could have been stamped on the day it was received as a promo at the radio station or wherever it was sent. An alternative scenario could be that the date is stamped by a ‘plugger’ as an indication for the DJ as to when the single was available e.g. the record is played and the DJ say something like ‘…and if you like that, it’s available from January 4th…’ Pure speculation of course.”
More from Alan Mansfield:
“Further to the R&TJ Deseri promo with the Jan 4 – 1969 date stamp – I have learned that the USA magazine Billboard dated January 4th 1969 carried a full-page advertisement for this single, which ties-in with the date stamp.”