Paul,

What type of varnish or shellac should I use on this? part is finished
except for trimming the outer ring off by hand and filling a few knot holes.

Larry

You can still buy shellac and shellac is the traditional stuff.
There may be something better out there since 1947 but I do not know
what that would be. Three coats of shellac are called out with fine sanding
between coats. Then waxing is called out.

That pattern looks wonderful Larry. I am sure a lot of people
will join me in thanking you for this wonderful effort.

You have done a great service to the cause of furthering rotary engines
in aircraft.