I am getting conflicting information about which finish to
use on the soundboard.  I am about to finish reshimming the
board.  The top surface will be sanded to bare wood.
The piano is a 1927 Chickering grand and the original finish,
I suspect, is shellac (light orange coloration).

I have been told:
        - "most rebuilders use polyurethane, but DON'T USE LACQUER"
        - just use shellac (white)
        - coat with shellac, then with topcoat with lacquer.

My goal is an authentic and lasting finish.  I am inclined to
use shellac (white), which will turn slightly amber with age.
I probably will be brushing the finish on.

There obviously is more than one approach.  What is the current
wisdom on authentic finishes?  I have no intentions of redoing
this soundboard again until at least the year 2050.

Larry Toto