J.A.M Records was a product of Beck Stdios, of Wellingborough. and presumably a private pressing; the markings in the run-off say that manufacture was by Deroy. At least one record was released on the J.A.M label. 'Kerry' by The Chantells, which was issued in 1977.  The catalogue number was J.A.M.-001; the 'A' and 'M' of the prefix may reflect the fact that the record was arranged by A. Kicks and M. Lock. These Chantells weren't the Reggae group of that name. Thanks to Robert Lyons For The Info.

77 The Chantells Kerry J.A.M J.A.M 1