The Sesquicentennial IPA marks the end of 150 years of production in Wolverhampton.
The tree in Stoke Bruerne will be cut back rather than removed after opposition in the village.
Terry Cole, landlord of The Royal Oak, says it will be a shame to lose heritage beers like Banks's Mild.
Volunteers at Kirkgate collect keepsakes and photographs from ex-staff for the exhibition.
Carlsberg Marston said the decision to shut Banks's Brewery in autumn 2025 would still go ahead.
Marston's previously announced it was selling its 40% stake in Carlsberg Marston's Brewing Company.
Camra says the firm's decision to sell its 40% stake in a brewing company is "a worrying development".
Marston's sells its 40% stake in Carlsberg Marston’s Limited to Carlsberg.
Owner Carlsberg Marston's said the brewery needed expensive upgrades to be competitive.
