Import the model into UVMapper classic (free) or pro (file/open), if the model has been mapped the mapping will display... go to file/export texture map and choose your settings. If the UV's are overlapping maps try selecting by group or material in select and hitting the bracket keys (I'm on a mac so the keys might be different) to selectively hide and unhide regions before generating texture maps. You can also scale and drag various parts out of the way as an option.