1694-1695: Building of a 2-manual organ by Arp Schnitger, with a free pedal.
1705: Repairs by Otto Meyer.
1712 and 1719: Repairs by Otto Dietrich Richborn.
1738: Repairs by August Wilhelm Bünting
1749: Enlargement by Johann Dietrich Busch
1780: Enlargement by Johann Paul Geycke.
1834: New organ by Hinrich Raschke.
Source: https://de.wikipedia.org/wiki/Dreifaltigkeitskirche_(Hamburg-Hamm) Old Postcard