Heritage auction archives would be a good place to look at the MM placements for these. The CC's are all over the place since each working die was punched individually, and it was single C punches so even the spacing between the C's varies considerably (as well as different sizes and styles of the C, as seen in your two examples). I could be wrong, but the only time I'd expect exactly the same position and size for both 1874 and 1875 is if the reverse die was reused across years.
I'll add that you should be very wary of counterfeits in this series. There seem to be a lot of CC fakes going around lately. I can't say for sure on these but on the last one the lower denticles look suspicious to me.