[Kurfürst]

Indeed as Juha says, the "110A" is almost certainly planes with DB 601A (B-4) and the "110N" are planes with DB 601N (requiring C-3). I suppose if there were mixed 601A/601N units then they probably used only C-3 in all planes, to avoid nasty accidents.

I suppose Bf 109E (many if not most of the E-7 were built with 601N) and F-1 or F-2 (all DB 601N powered) would be the other C-3 users.

All the rest could do with B-4, but at the same time could use the better C-3 as well, but not vica versa; there are, for example records of Ju 88A shoot down in the BoB found with C-3 in the fuel tanks, though B-4 was perfectly sufficient - and prescribed - for it's Jumo engine.