I normally do not collect Uruguay, especially these... though there was another pearl denom (see below) spotted in Santiago a few years ago that I would be interested in
The monogram used to be cataloged as Cuba about 20 years ago since that's where a few MOP denominations turned up which, doesn't mean too much since stuff does travels, not matter what it is.
Not sure how old the monogram is, though... I'll submit my chip when I receive it... and it's pretty much considered Uruguay by locals.

ChipGuide image...