Rebuild of 1904, 1943 Kilgen pipe organ. Releathered Kilgen ventil, unit, and offset electro-pneumatic windchests. Added three ranks to great division. Replaced added swell 8′ Trumpet with vintage 8′ oboe. Installed Peterson multiplex relay and 32 level combination action.

The organ at Lafayette Park remained in essentially its original state until 1942, when the instrument was rebuilt by the Kilgen Organ Company (the successor to Geo. Kilgen and Sons), at a cost of $2,885 (a great sum for those times). The original tubular pneumatic action was replaced by a more reliable electro-pneumatic system, a free-standing console replaced the original fixed console, allowing the console to be moved to more convenient location, an additional 12 notes were added to each of the Swell treble ranks of pipes, and a second extension was added to the Pedal section. The pedal board was also expanded to 32 notes, and the organ was re-tuned to current standard pitch of A-440 from the original A-435. The present set of couplers was also added at this time. Due to the extensive changes, the instrument was given a new serial number, Kilgen Opus No. 7050.

A number of minor changes and additions have been made in the ears since World War II. A 21 note set of chimes was added in 1945, a gift from Mrs. Robert Williams in memory of her husband. In 1971, the original Swell Oboe rank was replaced by a Trumpet rank by St. Louis Pipe Organ Co. A few years later, a 73 note 2 2/3′ Larigot rank was added. In 1979, Louis IX Associates revoiced the Swell Stopped and Harmonic Flute ranks, added an extension to the Larigot rank (creating a 12 note 1 1/3′ Quint), and added used 2′ Fifteenth Swell and 8′ Principal Pedal ranks. Later, a set of used Gross Flute pipes was added to create a 4′ Choral Bass Pedal rank.

The renovation undertaken in the summer of 1999 is the second most extensive in the instrument’s history, performed by Quimby Pipe Organs. In addition to repairing and/or replacing most of the mechanical and electronic parts of the organ (including replacing the 1942 electronics in the console with modern solid state electronics), several important changes were made to bring the organ back closer to its 1900 sound, and to include some additional ranks thought to have been postponed from the original installation. The 4′ wood Choral Bass Pedal rank pipes were replaced with a 4′ metal Octave rank; the 2′ Fifteenth Swell rank was replaced with a 2′ Flautino stop and the Larigot Swell rank was replaced by a 2 2/3′ Nazard stop (these are now extensions of the 8′ Stopped Diapason rank); the 8′ Swell Trumpet rank was replaced with a 8′ Oboe rank (reverting to the original configuration), and three new Great Organ ranks were added – a 4′ Flute d’Armour, a 2 2/3′ Twelfth, and 2′ Fifteenth.