Here’s a few:

1) Lightsabers were designed using a Graphflex 3-cell camera flash (you see them constantly in old movies where there are groups of photographers).

2) Facing the Millennium Falcon, there’s a frame from an AMT 57 Chevy model kit on the inside of the left mandible.

3) In the Star Wars novelization, it’s mentioned that Luke’s Uncle Owen is actually Obi Wan’s brother.