Thank you Jeff- I appreciate the link. I don't know why I didn't do this earlier, but I cross referenced the part numbers on the "DD" labeled coils and the "DD-FC" labeled coils. They both match- so indeed all Axiom DD's are actually DD-FC! You saved me a few hundred buckaroonies!
Took out the Axiom this morning to a salt beach (second time using it)- and the screen doesn't work?!?!?! I previously had this on salt mode, thankfully, and was still able to adjust the sensitivity and volume to pick some coins, trash, and lots of iron. I'll have to send this in for the warranty. Manticore in route... Excited to see what the Iron Check capability can do on the Axiom- this would save a lot of time and is a game changer.