I pulled some legos out of another set, and Lego is sending the missing pieces. Just two more steps to go.
@justinarticulate I went to the help section on their site entered the product number and selected what was missing. They notified me yesterday that they were shipped out.
So far my experience is I end up with a lot of spare parts. With this set, I have at least 20 extra pieces. On the Trench Run, there was 24.
@BenjaminSpider Did you get replacement parts directly from Lego (and how?) About a year ago I needed some specific pieces I lost, and I discovered the ecosystem of brick sites like brickowl.