The C and D parts and gear items have no useful purpose after playing for some time. I suggest that the players be able to combine them into a game of sorts. 10 C and D items can be combined into a token. 10 tokens allow you to open one of a grid of 16 chests. The prizes can be (but not limited to):

1- 1 red gem

2- 5 red gems

3- 10 red gems

4- Less than10 blue gems

5- Between 10 and 50 blue gems

6- Between 50 and 100 blue gems

7- B parts or gear

8- A parts or gear

9- S parts or gear

10- Ideal part or gear voucher

11- Ship voucher

12 through 16 are empty chest 

This allows the player to have a small game of chance for excitement