Dymak
Player Valuation: £40m
120 days or less between the end of one season and the beginning of the next. It would be a very impressive construction schedule to pull off the roofs of the Main Stand and Park End and replace them with ones that do not obstruct view. Even doing one each per summer would be no small feat. If you know how to do that in less than 120 days, you know far more than me, friend.
We replaced the Gwladys Street roof in that time frame in 1987. The Gwladys is on its third roof, I think. Sheffield United also replaced a roof on their away end in order to remove the obstructions, and I don't think it took them very long to complete. I can't remember too many examples of adjacent stands needing to be closed due to the construction or redevelopment of a nearby football stand either.