Initially in 1944, MW-50 boosted DB 605s (AM, ASM) would run on C-3. Butch noted some time ago that by late 1944, they were too capable of running at high boost (1,7ata), but with B-4.
Early-war British reports speak of 92 octane fuel found in the tanks of LW aircraft, appearantly it was some sort of mix of B-4 and C-3, altough most of the planes could happily do with B-4. The DB 601N, of course, only run on C-3.
http://kurfurst.allaboutwarfare.com/...asheets_N.html
As Ruy noted, the DB 605 DB / DB 605DC (same engine with different settings) with either B-4 (DB) or C-3, with a confusing array of power outputs.
http://kurfurst.allaboutwarfare.com/...eets_DBDC.html
Additionally, there were early D series engines marked with 'O' (ie. DMO), probably standing for Oktane, which could switch the fuel type readily. BMW 801D series engine also used C-3, and appearantly He 111H bombers in late 1944 also used C-3.
More stuff:
http://kurfurst.allaboutwarfare.com/...roduction.html
http://kurfurst.allaboutwarfare.com/..._Archieves.pdf
Can you post a picture of this fuel hatch, it sounds interesting.