The finish is lacquer - past the late 20's nothing else was used for radio cabinets. Production lines can't wait for shellac (let alone varnish) to dry. Lacquer thinner may remove any residual paint as well. You may find it's toned (colored) lacquer - you can buy this in spray cans too. The best place to ask questions about this is the forum at antiqueradios.com.
When you get to the electronic restoration, the Philco service bulletin is on my web site:
http://www.audiophool.cjb.net/Philco.html
The plastic parts (knobs, bezel and push buttons) may be available from Larry Bordonaro -
http://antiqueradioknobs.com/partlistings.html