[Dynamik]

I'm looking for some help in determining the difference in value between a 993 with service records and window sticker vs the identical car without records and window sticker. The short story is I bought a 993 C4S and part of the agreement/contract was the service records, including the window sticker, would go with the sale of the car. This was a private party sale. So I fly in, full payment made, pickup the car, and the owner informs me the records are in storage and he'll gather them shortly and send them to me. So 15 months and many e-mails and phone calls later I still do not have them. This is clearly a breach of contract along with a few other items promised in the sale agreement. I can quantify the value of the other items but I need help determining the diminished value of the car as it stands without service records and without the window sticker. This is heading down a legal path so I need more than opinions, something that can prove cars like this with records and original window sticker are more valued with records than without.