Suspect that is Burnley who took 32 years from 1960 to 1992 (winning them in reverse order).
Wolves have won all 4 in about 50 years and Preston in 106 years, but they both also won the top flight title before winning lower leagues.
It depends on whether you only count the post Premiership football league structure.
Being purist about this, Wolves won Div 4 in 88, Div 3 in 89 and Div 2 / Championship in 2009, taking 21 years.
If we win this year (and that is still a pretty big if right now), then we could do it faster...