I have done several plastic actions for Fischer, Chickering and
others.  Everyone I did needed new jacks, new backchecks, new damper
levers.  I was not about to sit and install new jacks and backchecks
onto the old wippen.  The best way is to get new wippens with jacks and
checks already installed.  While it is more money, it saves money in
the long run by not having to pay for your time replacing small parts.

It also will need the dampers done, and the hammers are seldom usable.
You are replacing the entire action not just a few flanges.  It costs
substantially more than previously quoted here on MMD.  It is just as
much work as replacing an old piano action except for stickers which
are not there.

If you can find one that only needs flanges, then good luck, it won't
cost much, but you cannot leave _any_ plastic as it will shatter at the
slightest use.

D.L. Bullock    St. Louis
http://www.thepianoworld.com/