I'm certain I can demonstrate beyond a reasonable doubt that this image is mine. That said, here's what I've done so far:
Consulted two local pros with prior experience in infringements.
Registered the image online at copyright.gov
Saved e-mail & web page to HDD (in case they pull it down and deny use)
Researched value based on usage through several online stock companies.

The average value based on size (over 728pixels), minimum distribution (under 1000), and run time (1 month or less) is $930 x 2 = $1860.00 (the x 2 is because it was used in two separate and distinct places/ways.

Both pros agreed that talking to the studio first would not be shooting myself in the foot legally, and that it was fine to negotiate as long as they offer something of equal value. If that goes well and they do the right thing - problem solved. If it doesn't, it's time to have a lawyer send a cease & desist and request damages of 3x the current market value. If that doesn't get their attention, it's on to Federal Court which *could* impose statutory damages of up to $150,000 per infraction plus attorney fees. I'm hoping they just do the right thing when I meet with them though, even if they trade it out in studio time/equipment rental/whatever.