Steering wheel: Original old ivory steering wheel (usually called Bakelite), not restored, old Mercedes stock item.

The traces of long storage were completely removed by cleaning and polishing. 

Brackets: The old original brackets are also perfectly preserved

The quality levels:

Restored steering wheel: Old plastic, mostly cracked, has been refurbished. After a good job, a nice steering wheel.
  Advantage: cheapest price.
  Disadvantage: The plastic shrinks further when exposed to sunlight, causing cracks
  go back on.

Reproduction: Reproductions mostly produced in the Far East.
  Advantage: low price, new plastic that won't crack.
  Disadvantage: Deviations in shape and color, sometimes no operating license.

NOS steering wheels: old stock items from Mercedes Benz.
  Advantage: Old new product, so no deviations from the original steering wheel.
  An investment with added value.
  Disadvantage: High purchase price because it is very rare.

Used polished
Steering wheels: Old goods in good condition, usually due to longer storage and selection
  Advantage: Original old goods in very good condition, no tearing, cheaper than NOS
  Disadvantage: Possibly slight signs of wear

Plastic re-cast: The old plastic was completely removed and replaced with new one. This means that the original old steering wheel is retained and has a long service life.