Odd half-shell snail with two bony mouthparts

[A.m.P]

Not sure what this little guy is, bigger than most of the small limpets I have in my tank. Has an irregular shell perimeter, and is remarkably flat -stomatella shell flat-.
The foot is also divided into two strange and visible regions where you can see through the body and into the musculature down below. 

To top it all off the animal has two bizarre calcified teeth-like bits up top and doesn't really have a typical grazer mouth at all, the white teeth-like areas glow under the blue and UV like I'd expect from the inside of a shell, speaking of which this dude's opalescent underneath and bland muddy-brown on the back of the shell.
The pearly-underside and weird, flat shell + mouth almost had me thinking abalone, but it only has two antennae, no clue what it is.

Maybe some kind of juvenile slipper snail?

[debbeach13]

No idea what it is but very cool looking.

[empresto]

Does the shell look kind of like a cone? Workout a picture of the top of it, I can't say for sure, but it really looks like a limpet to me.

[A.m.P]

11 minutes ago, empresto said:

Does the shell look kind of like a cone? Workout a picture of the top of it, I can't say for sure, but it really looks like a limpet to me.

The reason I think it may be a slipper snail is largely because of the limpet-like appearance, but it's got an uneven, half-clam-esque perimeter and the "two-part body" with a bony mouth structure.