Dated July 1986. Possibly published in the Titan edition of Halo Jones published in that year.
Dated April 2001. Possibly reprinted from The Complete Ballad of Halo Jones published in that year.
Originally in colour but here in black and white. Also the image appears to have been stretched to a US comic ratio, so possibly reprinted from the Quality series rather than from 2000 AD directly.
Brief biographies of both creators.