Randy asks about replacing the spring in the Aeolian tracker fingers.

Yes, the springs can be replaced, but they may not need to be replaced.
I've brought many springs back to life by pulling one end of the spring
wire out with a pair of needle nose pliers.  This tends to open the
spring and increase its power.

Be careful, pull in very small increments and check for improvement.
These finger springs should not be very strong, as they could cause
damage the roll edges.

Bob Lemon
Lemon's Player Piano Service
Sacramento, CA