These two, neat, rose, GB Victoria, 3-d.(SG92/ Plate 4/NE & NH) issues were used at the British Post Office in Arica, Peru, between October 1865 and October 1867. From research done online, I found that the oblong, "C36," Type: 3TH.HOS obliterator(Rarity H/More common on single stamps--rarity E) was first sent from the GPO in London on 26th January 1865. It's recorded in use from 28th October 1865 to October 1867. 

To continue, as I bought these two stamps together, and they are both from the same line of stamps in a sheet, AND the barred numerals are both placed upside down, and appear very similar in the way in which they were applied at the time the stamps were struck, I strongly believe that these stamps were used on the same piece of mail, and amazingly, have been able to stay together all of these years! Two, different, partial cancels from different, foreign post offices can be seen on each of the stamps. The stamp to the left has a transit or receiving cancel CDS from Paris, France, at its top. The stamp to the right appears to have a cancel from a Peruvian post office.

Lastly, the stamp to the left is in very fine condition, overall. It still has some gum. The stamp to the right does have a few, shorter perfs around its top, left corner. There is also what appears to be a slight thin near the bottom, left corner of that stamp. A nice, partial, oblong barred-numeral cancel, "C36,"(75-85% complete) was applied to each stamp, the one on the stamp to the left almost complete! GB stamps used abroad from Arica, Peru, especially between 1865-1867, are very rare!