73 Challenger Seat Belt Question

I have a 73 Challenger base that only has lap belts. A friend just told me Massachusetts has a new law that says what ever safety equipment the car had on day one must be in the car today at inspection time.
The front lap belts have a button on the male clip that I assume was probably for a shoulder belt. Can someone tell me if my car should have 2 point belts or 3 point belts? There are no holes in my headline that would indicate there ever was a shoulder belt so I don't know if the lap...

73 Challenger Seat Belt Question
Author: Sparkey