The plastic key bushings are a waste of time, in my opinion.  Do it
right, and do it now.

Micrometer the keypins (which are probably .046") and order a set of
bushing-hole sizing cauls from Bill Spurlock (Spurlock Specialty Tools)
and a set of his key bushing cauls for this pin size, if you don't have
some already.  Plug the bushing slots with bits of thick felt soaked in
water, then pick out the original bushings with tweezers, and shove in
the sizing cauls while the wood is still damp.  Let dry thoroughly,
then pull out the cauls and bush the keys with some high-quality felt.
Bill Spurlock might sell that felt, or Pianoforte Supply, or Pianotek,
etc.

This method ensures good, uniform bushing tightness, with minimal
damage to the key wood and minimal adjustment later.  If some bushings
are too tight, use a set of key bushing irons instead of "easing
pliers" (which crush the wood).  I use Titebond Trim and Molding Glue
for gluing in the bushing felt, because it has a near-paste
consistency, which will not run or soak through (creating clicks), yet
is still easily removable by the method above for future rebushing.
For a glue brush, I use a small, flat, 3/8" wide hobby brush with
synthetic bristles.

Gordon Stelter