Try the Taubman's plans section of the Loyalhannah Dockyard site. They have a series of R/C combat plans that has a Mississippi listed, but that could be the BB-41. It really isn't clear.
Dang! I just looked and Maryland Silver doesn't have ANYTHING on Mississippi... I woulda thunk... Norman Friedman's US Battleships book has a single profile view line drawing of Mississippi as-built on page 48, but that's it. I will keep looking (off today, love that federal job!)(yes, I had to pay leave, but it's still a 4-day weekend!)
Well, heard back about the Taubman's plans, been informed they are not what I am looking for (assume that means they are of the later Mississippi). Will have to check out the Goff plans at some point I guess.