Martin Anderson wrote, "The tuba rank had weights on the tongues,
with the largest ones being attached with a small flat-head Phillips
machine screw."

Dear Martin and list,  I believe what you saw was not a Phillips head
screw but was a rivet with cross stamping to set it.  Phillips screws
do not originally show up on any Wurlitzer organ in any part of the
instrument.

Tongue weights were first used by Willis in England and their purpose
is to make the reed tongue swing wider and do so evenly.  That makes
the pipe louder with less harmonics, exactly what you want from a dark
smooth reed like the Tuba.

As for reed "buzz," all good organ technicians know that the
dimensional stability of the brass shallot is far more suspect once
you have eliminated the usual problems such as dirt.  Brass shallots
warp with age and have to be trued up with a good file.  Amateurs get
into trouble when they try to make a reed tongue fit a warped shallot.
You were right in calling in a journeyman organ tech.

Al Sefl