Beauty is in the eye of the beholder.

I did a search on Atlanta CL and found
THIS. I also checked oldrides.com, but nothing came up for a 1958 truck. Looks like someone sprayed undercoating on the floor trying to cover the obvious. If I had to throw a number up with what I know from the pics it wold be in the 1000-1500 range. That is an uneducated guess.

Good luck!!