Original, or knockoff?
That is indeed the question. The Boston and Sandwich Glass Company was not above creating knockoffs, it turns out! A case in point is Peachblow glass vases.
Several American factories produced Peachblow glass, which had a surface that shaded from opaque cream to pink or red, sometimes over opaque white. This glass was made in imitation of the Morgan Vase, a famous 18th-century Chinese peachbloom porcelain vase that sold at auction in 1886 for the astonishing price of $18,000. The sale was widely reported, and glass and pottery manufacturers raced to capitalize on the publicity by producing objects that resembled the famous vase in shape and color.
The Boston and Sandwich Glass Company was no exception, producing its own line of Peachblow items, imitating the Morgan Vase both in form and (somewhat less plausibly) in coloration.
I was asked recently whether a Peachblow cruet was made by the Boston and Sandwich Glass Company, but judging by the photos, it seems somewhat unlikely. The BSGC cruet has a cylindrical neck, whereas the item being asked about has a tapered neck. That, and the difference in how the two pieces are finished, make me question whether it came from Sandwich, or was produced by one of the many other glass factories that by this time were popping up all over.