Coin Parts:
External Coin head - size should be fine for 50c E coin. Some are stamped with a 5c in the metal - you can buy generic parts that don't have the stamp. I have also seen people turn them backwards.
CC16 - again the right size, you will need to change your sample coin.
Coin Optic - spacers are the big deal with nickles as they are a thicker coin, but so is the 50c E - so your good there.
Hopper Wheel - this lifts the coin - the previous post by RB covers this well.
If your having parts shipped I might suggest getting a spare hopper knife, Clear chip, Set chip - they weigh nothing.