I think I saw City play Leeds in 1956. No idea if Jack played, John Charles was the famous one in that team.
He did play:
Lincoln: Mitchell Downie, Doug Graham, Harry Troops, Fred Middleton, Tony Emery, Dick Neal, Jimmy Munro, Colin Gibson, Tommy Northcott, Tommy Bannan, Roy Finch.
Scorer: Neal
Leeds: Roy Wood, Jimmy Dunn, Jimmy Ashall, Archie Gibson, Jack Charlton, Eric Kerfoot, George Hutchinson, John Charles, Bob Forrest, Harold Brook, George Meek.
Scorer: Charles (pen)
Att: 13,713
The draw (on 3 March 1956) left Leeds in 7th place, but a great run of nine wins from their final ten games took them to promotion behind champions Sheffield Wednesday. Lincoln also had a good season, their 8th place being their highest league finish since 1902.