It is pysically impossabile to fit a full pan like you may already know, the two piece would be the better solution unless your welding skills are good then i would suggest the mothod of cutting in half like you also mentioned. No overlap of the panels this way, that is if you are after a 100% factory look of course.
The speckled paint may have to be ground off using a paint stripping abrassive wheel.
Post a picture of your trunk area if you do not mind so we can determine what would be the best methodology.
![2 Thumbs :2thumbs:](http://www.cuda-challenger.com/cc/Smileys/default/2thumbs.gif)