From Florence Hadley Heynen (29 Nov 1986): Places of business from NY city directories: 1822 Porterhouse, 231 William; 1826 National Coffee House, 224 William; 1828 6 Vandewater; 1830, 18 Gold; 1831, 100 William (h. 12 Vandewater); 1834, same; 1835, 100 William (h. 86 Nassau); 1836, 100 William (h. 19 Rector). She found no deeds, probate records, or death records. She did find an 1820 Census record and an emigration record.
From Beitrage zur Westfalischen Familienforschung:
"Erlaubte Auswanderung ... a) Heinr. Lefmann aus Warendorf, Kaufmann b) 6. 7. 1804 Telgte c) Witwe Elise Lefmann geb. Windmuller o) 1831 p) Nordamerika / New York s) Der Onkel Samuel Windmuller lebt seit längerem in New York."
Roughly translating as: "Permitted Emigration ... Name: Heinrich Lefmann [i.e., Henry Lefman], Residence: Warendorf, Occupation: merchant], Birthdate: 7 June 1804, Birthplace: Telgte [Telgte is a township in the Warendorf District], Parents: Widow Elise Lefmann, maiden name Windmuller, Year of Emigration: 1831, Country and Place of Emigration: North America / New York, Remarks: His uncle Samuel Windmuller has lived for many years in New York." Source: Beitrage zur Westfalischen Familienforschung (Verlag Ascendorff, Munster, 1966).