Just curious if I have identified this revenue stamp correctly. I assume I'm correct in that that there is enough of a margin all around to correctly reference it as imperforate, but I'm confused because the Scott Catalog refers to the R48a as "red". Is this merely a faded example or is the color "red" a blanket reference for any lighter shades as shown here?

Also note the cancellation of "E. Whitehouse, Son & Morison". Based on an internet lookup I guess they were a stockbroker and banking house back in the mid-19th century, located on William St., New York.
What is curious is the spelling of the name "Morison" with one "r". It is misspelled with two "r"'s more often than not in period documents.