The Fleetwoods were on Dolton Records. (You can see part of the logo underneath the price sticker.) Dolton Records and Liberty Records were both owned by Avnet in the early 60s and the Dolton catalog was eventually absorbed by Liberty in the late 60s (prior to the sale to Transamerica, I believe). So, the 1965 timeframe of this album fits.
So, that is a possible connection to Jan and Dean. It's very possible (and probably very likely) that the two labels shared the same art department. If it is Jan and Jill in the picture, it could have been an outtake from a J&D photo session that was lying around and someone decided to use it as a "generic" cover shot for this Fleetwoods album. Just a theory, but would make sense.
