HI there
I have V1 of YM. The changes are so subtle, that I'll stick to V1, which is a fantastic model as well.
As for YC, if the picture is correct here, the colors, size and position of the tail logo are wrong. I'd say is more similar to YA than YC.
YC has the definitive LH colors : lighter blue and larger/bolder circle right at the center of the tail, much like YZ.( B744 ). And last but not least. the Lufthansa letters on the fuselage should be thinner as well.
So, if the airplane model is as shown in the picture, I'll not get YC from NG by now.