"A Variorum Edition of the Works of Geoffrey Chaucer" was published by University of Oklahoma Press in the 1970s-90s. It was laid out as 8 'volumes' consisting of 39 'parts' (separate books), if I've counted right.
For instance Volume I is the variorum of the Hengwrt manuscript of the entire Canterbury Tales (and so is buried in the LT 'work' of the Tales), while Volume II consists of 25 parts -- 1 (or 2) devoted to each individual tale. Then Volume III is Troylus & Crisseyde; and so on...
I'm not sure if this series was ever completed.
UPDATE. The Wife of Bath's Tale in this series was published as recently as 2012.