My history of the BCP is a bit rusty these days, but if I'm not mistaken, Myles Coverdale, a priest and contemporary "reformer" with Thomas Cranmer had prepared a translation of the Canon Missae for use in the emerging "vernacular Masses" being done - without ecclesiastical or royal sanction - around the time of the English Litany's publication (1544?). He it is, also, I believe, who did the version of the Psalms that ended up in the 1549 and subsequent BCPs (they are not the KJV).
Indeed, even in the BCP 1979 preliminary documentation, the revisors note that they are sticking with Coverdale (as the basis for their "inclusive language" revision) because he was translating FROM THE LATIN VULGATE and therefore the stophic lines were longer (and more adaptable to both Gregorian/Sarum and Anglican chant).
As I understand it, that Coverdale Canon is at least the basis for what shows up in those Anglo-Catholic "English Missals" (W. Knott & Son) of the early to mid 20th century - and, I could be very wrong on this - THAT becomes the basis for the Roman Canon translation that eventually went into the Book of Divine Worship.
If you haven't yet seen one, you really ought to track down a W. Knott English Missal - especially an altar edition (some older Episcopal priests have them) - complete with the entire Tridentine Ordo Missae, the Roman Canon in LATIN and English, all the prefaces set to Gregorian Chant, and all the Masses of the Missale Romanum including Ss John Fisher & Thomas More, Votive Mass "for the Election of the Chief Bishop" ("grant unto the holy Roman Church a Pontiff . . . ").
Amazing.
Makes you wonder: If they wanted a beautifully produced (text and layout) Missale Romanum in the vernacular, why didn't they just approve this?
Truly fascinating! Thanks so much for the info! :)