Mexican Stamps With And Without N Before Denomination

No photo.

I have a Mexico Valle de Bravo stamp with denomination of 2.70. circa 1997. There is no capital N in front of the denomination. A search shows that the N stands for Nuevo or New meaning that the value changed from the prior value. All of the other stamps of 2.70 value have shown the N in front.

I have found other denominations such as 3.70 and 4.70 without the N but no other 2.70. When is an N placed before the value and is the 2.70 that I have anything special.

Thanks Popeye

Can't really help you without a picture.

Mexico, Scott 1782-1805, Tourism in states of Mexico series, has a note after it to also see 1960-1980, 2119, and 2122-2140.
Under the 1960-1980 grouping is another (oddly placed!) note of "Denomination of Nos 1782-1805 was shown in N$."
Thus it appears you have found stamps from more than one grouping of this long set.

No picture, not even a catalog number ?


Peter