I used to have a book with paint formulas but it is gone.  Looking up
furniture lacquer and automobile lacquer in the Hiscox and Sloane book
of formulas, 1949 edition, does show a few formulas and most of the
ingredients are not that difficult to find and are not especially toxic.

I think there was a gradual evolution from the classic formulas, shown
in this book, to more reliable and controllable ones that contained
'nice' things like benzene and methyl ethyl ketone (MEK).

The one ingredient that will be a problem is the nitrocellulose itself
which the book refers to as "cotton" [guncotton].  This was presumably
readily available as there is no formula for making it.  It is pretty
simple: just cotton, sulfuric and nitric acids and acetone.

The stuff is very flammable so some care is necessary and you also have
to make sure you neutralize any residual acid before making lacquer out
of it.  I would give links but I prefer to let anyone craze enough to
try it, to find them on their own.

I also remember that people used to make their own lacquer using old
cellulose based movie film.  If there are any of these left in totally
deteriorated condition, they may be a source of nitrocellulose.

I have been reading the book, "The Steinway Saga", which traces the
history of Steinway from the beginning to about the late 1980s.  It
is stated (but might not be true) that Steinway was the first to use
lacquer (probably in the late 1920s) and that all pianos used varnish
as a finish before that.  Now everyone uses catalyzed finishes which
will be real fun for future restorers to have to deal with.

Best regards,
Spencer Chase
Garberville, Calif.
http://www.spencerserolls.com/ 

 [ Nitrocellulose is very flamable.  Google: nitrocellulose fires
 [ There's a nice PDF file from Dow on the handling of nitrocellulose:
 [ http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_03e2/0901b803803e284e.pdf?filepath=/822-00001.pdf&fromPage=GetDoc
 [ There's also an interesting article on Wikipedia.  Read the section on
 [ "Nitrate film" at: http://en.wikipedia.org/wiki/Nitrocellulose   --Jody