During the restoration work on the organ in the 1970s, the following information was discovered: The organ was a two-manual mechanical action (tracker action); an instrument of twelve ranks of pipes with a total of 764 pipes. The organ was originally pumped by hand by a lever on the side of the organ on the rectory side of the Chapel before electricity was installed in the building and also at one time it was pumped by a water pump, which worked the hand level by water pressure.
The organ was rebuilt in 1955 when all of the original mechanical action was removed, and new electro-pneumatic chest work and mechanism was installed. However, many of the original Silberman pipes were used in the existing organ before its restoration, but the size of the instrument was reduced to about one-half or 305 pipes.