Normal Vector Problem When Use ProOptimiz Modify

Explain :)

ok let's explain : please read thanks :)

we got a 3d modeler about 2 year ago to make about 50 3d car model ,we pay every month cash to he, but a few before complete 2 year and give us all models he leave us and join another company in same race car game type and wont give to us 3d models but give to another company,
in final after a while we got 3d models, but it's to late ! cause another company use that's models in it's game first release , now if we use this models that's company make problem about copyright laws for us cause our vertex and faces are so same of they 3d game models ,
now our solution is use ProOptimize to merge some faces automatic but keep original 3d model form of car.
this is big problem for us don't know how to solve it...

graphics and game play of our game is sames to DriveClub and GranTurismo last version with dynamic time of day and many more option & etc..
this is a real time in game screen shot of our game :)

http://www.uppic.com/uploads/14208054811.jpg

http://www.uppic.com/uploads/14208054812.jpg

so now if u help us in any way i promise to do any thing u want and we can.

we need a script to change vertex pos or faces of a 3d model but don't changes shape or form of 3d model :) i can send a sample model to u also.

if u need anything more let me now please.