I agree with Dave Vincent.  Hoyt metal is used in organ pipes.  Normal
pipe metal is spotted metal.  When the tin and lead alloy cools spots
pop out on the top surface.  This is a pleasant enough look that most
organ pipes from this are left spotted.  In some organs where the
facade pipes are not to be painted gold or aluminum, or gold leafed
they make the Montre, or show pipes (usually diapasons) out of Hoyt
metal because they look like they have been nickel plated.

Ruffatti is one builder who uses Hoyt metal extensively in their facades.

D. L. Bullock    Piano World    St. Louis