Two separate issue here:
1. Legal situation. Fraud has occurred, which not only affects you as the buyer, will also affect you as the seller if you try to get rid of it, since the odometer fraud has occurred. I know you have concerns about lawyer fees but I would at least go talk to one to discuss potential options. If there is some legal recourse to recover your money, I would explore that, keeping in mind that $16K won't buy you a 100 series of any year with 70K miles even if in this soft market. Low miles (sub-100K) are super rare these days in the 100 series and examples command premium prices. So also something to think about if you're looking to replace this one with another one.
2. REAL Condition of the vehicle. Mileage is only ONE indicator of condition but not always the the biggest factor. Maintenance schedule and records are also critical. As others have pointed out, 281K is definitely not a deal breaker on a very well-maintained UZJ100, especially one that's never been in the rust belt and has no accidents reported. But you will need to investigate whether critical maintenance (timing belt, for example) has been completed. You'll also need to understand if expensive components (steering rack, brake master, alternator, etc..) have been replaced.