Tim,  Generally if the tuning pins are holding, new treble wire won't
make a significant difference to justify the expense.  New bass
strings, however, can really spark up the tone if twisting them does
not do enough.  Also, this is the time to do it, before the player
mechanism goes back in.

I strongly recommend GC Piano, Toronto, Ontario for new bass strings.
Get a tech to help on this one because a piano tilter makes the job
easier.

Regards,

Jon Page