voicing up

[Mike and Jane Spalding]

List,

Today I tuned a Kawai 500 (5' 8" grand) that I had regulated and voiced about 6 months ago, a teaching piano that gets a lot of use.  She asked if I could do anything about the C#6, which didn't have near the power of its neighbors.  Here's what I did:  Listened, dull attack and short sustain.  Neighbors ring bright and long.  Swapped hammers with D6, dullness moved with the hammer, put the hammers back where they belonged.  Polished with 1200 grit silicon carbide strip, some small improvement.  3 needle stitches in low shoulder, no effect.  Ironed strike point, tiny improvement.  Re-pinned, went from infinite swings to 5 swings, some small improvement.  Filed off a layer of felt and polished with 1200 grit, significant improvement.  Final result, much improved, but still not as bright or long as the notes above and below.  The question is, What can I do to bring this note up without lacquering it?  Left on my own to decide, I would keep filing and polishing, maybe do some ironing after that.  Is this a good approach?  What would you do?

thanks 

Mike Spalding, RPT