[WW#254 cover by Ross Andru (1979) --- FF#293 (1986)]
FF#293 was Byrne's last issue of his historic run, however he did not do the cover chores for this issue. Looking inside, there is no credit given nor could I find who did it by searching online. Many fans speculate Michael Golden, Ron Frenz, Jerry Ordway or Al Gordon, but who knows for sure. Hmmm, if I had to hazard a guess, I'd say Frenz???
Side note, HERE is Byrne's rejected cover to FF293.