From his 1977 album One World.
John Martyn 1978 Rock Goes to College - Reading University - BBC. This is a fantastic rendition of Dealer from the album One world (1977). I left in the bit at the ...
top of the pops old grey whistle test 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 ...
BBC Sight and Sound in Concert 15 October 1977.
Found on the promotional Dancing 7'' single. Ripped by some legend on a torrent site, uploaded for you here.