The AP1730A Vol ! gives the Mk III sight as up to 1,000 feet. The Mk XIV was 1,000 to 20,000 as of August 1943 increased to up to 25,000 by April 1944. The T1 was the Mk XIV manufactured in the US using US processes but was functionally the same. I'll see what I can find on mine bombloads but not sure I have much. The internal fuel tank is interesting with the trade between bombload and range. Norden was not used and would have been inappropriate with its requirement for a steady bomb run-in. A few RAF specialist bombers needing accuracy used the SABS sight e.g. 617 Squadron but I don't think Coastal ever required that.