I've identified this conical-font pewter whale-oil lamp, and other pewter lighting of ca. 1840 as the work of anonymous Boston-area maker, I've dubbed "Crackbottom" in honor of a short, diagonal line caused by a crack in the mold used to cast the underside of the bases.  The cast line is barely visible in this instance, but "Crackbottom" was one of the only makers to create pewter whale-oil lamps with conical fonts and this one matches more plainly identifiable examples.    Height 6" to burner. Hairlline to bottom of shaft, and what appear to be plier marks near the burner, otherwise very good condition.