That '58 would definitely be worth redoing, if it needs it! Like they said, Cameos went to the first part of the 1958 model year, and it's probably the real deal. There in no difference in the VIN to differentiate a Cameo from any other 1/2-ton truck. I had a '55 that I bought for $200.00 back in 1988 or so. One of the years (don't remember which, may have been more than one year) had the hood chrome spear read "3126" instead of '3100".
Sounds like a keeper, in any case!