Same amount of seasons according to here - https://www.european-football-statistics.co.uk/englandcontent.htm
Though thinking about it there was obviously less games in the 19th century lol. Their last top flight season was 1961 apparently
I always remember from the football history books, that Preston were the first team to do the double, and that was way back in 1888/89. So like you say probably less games.
My memory of facts must be failing though, because I thought that it was three teams that done the double up to and including Arsenal in 1970/71...the other being Spurs in the 60's. Somehow my memory failed on Aston Villa's achievement soon after Preston.

