If you're an honest person, assume that your job under that director (and probably at the company entirely) was over as soon as they asked you to make a fraudulent engineering statement. Even if they backpedaled when you resisted, you're not a team player with them, and you're a threat to someone very dishonest.
At that point, options:
* just leave;
* consult a labor attorney (you can get a free initial consultation); or
* go above the director's head, probably (in a small company) to the owner/CEO, whatever attorney is on staff or they retain, or HR (though, you're still probably over at the company, even though they'll diplomatically pretend that you're not, because you are in 100% corporate butt-covering territory now, in a place that puts someone very dishonest as a director).