If you are going to attempt to 'fix' it, then you should be starting from scratch. It will end up 1000x better if you start from scratch, with proper references and spend about 1/2 the time planning before you even start up the editor.
Agreed with Jonny... yes its a good map. Yes its old and could use a revamp. But same could be said for most all maps... the revamp would be so great you might as well start another based on real al basrah and go from there.
duckhunt is aware its outdated but he has other projects going atm... but I do believe dr.rank made some edits to albasrah, not sure how much or if they will ever see light of day.
What I'd love to see is the detailing of Fallujah West, especially the west part with compounds, ditches, berms and bridges with all enterable houses, but on a 2km scale (like al basrah). Would be epic map.
And of course we got Sangin which is 4km goodness of same variey