Mate if your happy that the work has been done to a high standard and the car is running true then I wouldnt let it bother you that its cat c or d. How many motors out there have been involved in accidents throughout their lives and end up bodged back together?

I just think at the end of the day its just metal and no matter what it can be repaired.. I mean just look at some of the restoration type jobs that people do on cars nowadays...they cut the car into little parts, and they put it all back together to such a high standard.

Think as mentioned above about keeping photos of the work is a good idea because you can show any potential buyer the pics and say this is the standard of repair.

Did you have any autolign inspection done on the car?