Thanks for all the suggestions, guys.  I ended up buying another clear shell and am going to figure out something different to do with the primed one.
Your collective help is always appreciated!

Just finish spraying the primer nicely and keep it as is.  Put some stickers on the outside and some colofull buttons and I'm sure it'll look dope.  Learn from your mistakes and embrace them.

Or paint it from the outside so it will look like a non transparent case and sell it then use the money to get another transparent one.

try denatured or rubbing alcohol.    Simple Green is also effective at removing paint.

If it's a clear shell, you're better off getting a new one.

Do you have any suggestions for  all those pesky nooks and crannies?  There's a lot of really hard to reach places with sandpaper and I fear my file kit is too coarse

Yeah...  I was hoping it wouldn't come to that.  I don't want to have to abandon a clear shell, but it may not be worth my time.
I figured I would pick your collective brains before shelling out, though.

Honestly, buy a new shell.

Wet sanding.

Hey all,

I'm attempting to paint the inside of a clear DMG shell and I stupidly applied primer without thinking.  Anyone have any experience removing primer from shells?

Many thanks!