I've had this Philips 633A radio for a number of years and never did anything with it. It was made in 1953.
It works but needs switches cleaned and some caps.
I went looking for a schematic and found an interesting web site that had the 24 page service manual. It's in Dutch but a schematic is a schematic. The web site has many foreign radio schematics for free. You do have to register (it took me 2 minutes). Check it out.
http://www.radiotechniek.nl/