This registered cover was mailed from Yokohama.
The only evidence, however, is the circular violet REGISTERED datestamp on the front.
The stamp was not cancelled until its transit through New York!
I believe the red registry number 5463 was added in Yokohama.

The cover entered the United States on October 3 in
San Francisco (note the red three straight-line REGISTERED mark on back).
The San Francisco post office also added the blue 95332 serial number.

On October 10 the cover arrived in New York City.
There a preprinted registry label was added, the stamp was finally cancelled
with a black circle-of-wedges fancy cancel, a black oval New York Registry Division
datestamp was applied, and an interesting black large D in a circle with
the date 10 | 10 inside the D and 87 inside the circle was added on the flap closure.

The cover finally arrived in London on October 20 where
a red oval LONDON REGISTERED stamp was added.
I believe the violet boxed bold R was also applied in London.
The London post office also added the customary pencilled blue cross.

I cannot explain the various pencilled blue numbers other than to say
such marks were often added as handling marks by post office personnel.

The cover was franked with an 1877 10 s. blue design
incorporating the imperial crest and kiri branches (Scott 62).