They cant get you for spacers unless the spacers fail. There's laws protecting you for that stuff. If you put a sticker on your bumper and it fell off, could Ford say its your fault because you put the sticker on? No, they have to prove it was cause of the sticker.
Spacers are sortof a nono to run though. They're a possibility of failure and its much better to find rims that work. I'd check ebay though, because 1900 is a lot of money. I'm sure you can find some great Ranger rims.