You state that every Lanc ever made stayed like that?
Are you stating that every Lancaster that was ever manufactured with three turrets stayed that way for it's entire career and that no Lancaster except the ~30 specials ever had some of their turrets removed and plated over? How do you explain the two pictures of Lancs that are clearly NOT specials, one that you posted a link to and the one's picture that I posted, that have both had the top and ventral turrets plated over?
But why bother arguing whether 1/4, 1/3 or 1/2 had their turrets removed when the correct question was which aircraft had the superior aerodynamic performance? (With or with out those turrets!)