Make your old internal drive an external drive!
This is an external enclosure for a UJ-875 internal laptop optical drive*. You will also need a JAE 50-pin to USB adapter. Use as is or finish top and bottom with profile cut lids (as shown).
For a full write-up, visit http://weareunrivaled.com/3d-printed-drive-enclosure/ .
*drive shown came from 17" model MBP, c. 2008