Guatemala Early Covers

The early Guatemala stamps on covers are quite rare. I search quite intensively in the auction catalogs all the time. I just don't find them. Guatemala I by Goodman lists those known covers. Here is one I acquired recently, which is inventoried in Guatemala I, as one of 7 recorded covers. This 1876 cover, franked with a 4 Reales stamp (Scott #5), paid a double-rate letter, sent from Guatemala via the Pacific Mail Steamship route to Acapulco, Mexico.

Very nice. The climate is very humid I would think so that accounts for the mould on the cover and stamp perhaps, probably.

I like that red / magenta Paquettes cancel. That would be from the ship trasporting the post, yes? Packet Mail? Previous to the UPU decision in 1895.