I was sorting through my box full of tombstones prepping for a big Death Star game for two each of numbers 1- 28 when I couldn't find any number "20's". I have atleast one of every model and on average 3 of each. Was number 20 skipped or have I misplaced them?

There is definitely a set of 20s, as I use a 31 day pill organizer to store the first 31 sets of tokens, and I have it filled.

As for which ship expansion it came from, I couldn't say for certain. It would likely come from wave 1 or 2.

Just checked wookieepedia. #20 is the falcon.

Just checked wookieepedia. #20 is the falcon.

In this case you don't need to worry too much. Just pick up a copy of Heroes of the Resistance when it comes out. There should be another set of 20's in it since its a Falcon pack.