Jewelry to be used in new movie

This is way out of my circle of expertise, so I’m hoping someone can
shed some light.

I just received an email from the Prop Master of a film being made
about Cystic Fibrosis, and they’d like to buy a couple of my pendants
to use in the film. (The pendant is something I designed specifically
for CF, and I donate my profit to the Cystic Fibrosis Foundation).

I’m thrilled, and from the info on the film he sent it sounds legit,
so I’m not concerned about a scam of any kind. And I don’t imagine
there will be such a run on them after the movie airs that I’ll be
inundated with TOO much work.

So I’m not seeing any problems, but I’m wondering if there’s any
precaution I need to take, any brief contract I should ask them to
sign, etc? I don’t want to send them the pendants, and then find
after the fact that I should have done something first. Any
thoughts?

By the way, I have a certificate of registration from the US
Copyright Office.

Thanks,
Cindy Crounse
Refined Designs