H78 is assigned to 1840 and H549 to 1844. H549 is also shown in the 1840–1850 watercolour.
Henry Astor is dated 1839–1849, although Nantucket Signals begins in 1840. David Thane owned her in 1844, William R. Easton acted as agent on both recorded voyages, and she was sold to San Francisco in 1849.
Keep the explicit scope label independent; no alias or company identity is inferred.