Can you ID this rust-free passenger door?

I bought this door from a soda shop that closed 8 or 9 years ago. They had it hanging on the wall for decoration with neon on it. (Notice the circles, those are the neon mounts).

Does anyone have an idea what this is? I'm guessing mid-50s somethingmobile - but need more specific info.

Need to know what it is so I can post a HAMB auction and make it disappear! Thanks!

 

57 buick??

 

Looks like a 58 buick door, but can't tell if it's for a 2 or 4 door.

 

I'm working a 24 hour shift, I can take more pics & get measurements if that will help. I hate the idea of throwing it away. The door hung on a wall with cardboard front & rear panels to make it look like a convertible. The cardboard has been gone for years, I recall that I paid $50 or $100 for the whole thing, got it home, got drunk & busted the neon tubing. Big mess, angry wife. I put the door out in the shop, it's moved with me 3 times, time for it to go. I'll do a HAMB auction when I know what it actually is. Just hate the thought of just throwing it away, and not real keen on hanging up for garage art - this thing is heavy!