hard leather

[Joel A. Jones]

I recently had an experience with leather bushings that had become hard.
If you moved the keys from side to side the clicking sounded as if there
was no busing, only wood.  The sound of a glissando was pretty amazing. The
piano is in a teachers condo where she humidifies and dehumidies the
studio.  Other than the leather problem the piano is in top condition and
serviced regularly.
         Following advice from several sources, I bought some mink oil from
our local leather store and put several applications on the bushings, which
seemed to lessen the clicking somewhat.  By turning the front pins the
noise was acceptable, but I'm not pleased with the final product.
         I suspect this problem will return in the near future. Has anyone
had any experience with;   1. applying mink oil to soften the leather
bushing.    2. longevity of the treatment.
        Thanks for any suggestions anyone may have.