What types/kinds of metals are inside the 340?

Why??? strange question, but OK.....
the rotating rack assemble has lot & lots of galvanized steel baby!

as is the tank/linet & inner door, test with a magnet if in doubt.
the evap' coil is copper coils & probably has aluminum fins, the vending cog & gear box housing is most likely cast zinc or aluminum, or worst case pot-metal last one I helped Pat Pixley restore the bottle guide-chute was aluminum as well.