[Nick Beale]

While I’m not familiar with 1941 files at all, there are two TNA series that might have something, based on what I’ve seen from later years. The Air Ministry W/T Daily Intelligence Summaries run in sequence from AIR 22/476; the G.N.A. (= German Naval Air) reports start at HW 13/27 and end at HW 13/42. Those seem to begin with just Y-Service material but go on to add info from ULTRA, plus occasionally knowledge gained from prisoners and wreck investigations.