N Number Size

[Charlie Nightingale]

I am just about finished on the restoration of N94125. The new N number will be N555CN, Approval has been granted for the new number, there seems to be various answers as to what size N number can be used. The aircraft will not be leaving U.S.A. , and I would like to utilize the small vertical N number on the tail. Query: Do I have a choice of either size or am I limited to only one size?? Any help would be greatly appreciated.  Thanks Charlie