The Rev B lens retainer ring will not fit inside of my Rev A 70º lens tube.
Description/Explanation of Issue
In the Rev A 70º lens tube, the retainer ring [7060A3186] and the rear plate [7060A3185] have three screw holes.
In the Rev B 70º lens tube, the retainer ring [7060A3209] and the rear plate [7060A3210] have four screw holes evenly spaced.
Due to the rivets holding the lens tube together, a 70º lens tube may not be taken apart in the field. Instead, the lens tube will need to come into the factory for a repair.