In the article about the new catalog of Argentina in Perfinpost 132, the find was reported by an unknown Argentine perfin RR&C.
To my surprise it turned out that this is a perfin from the Belgian company Richard Rhodius & Co from Antwerp, who was involved in trading skins and wool. The perfin was used between 1884 and 1914. The perforation fits exactly to the image in the Belgian perfin catalog.

Fig. 2: the perfin RR&C in the perfin catalog of Belgium

When inquired in Argentina, this company turned out to be unknown there. It is also unknown how this Belgian perfin could end up in an Argentine seal.
If you know more about this perforation, please let me know. Then send an email to Ton van Schijndel, webmaster@perfinclub.nl.