Looking for examples of 3 Point Seatbelts in 1964 Valiant

My buckets do not lock. Any aftermarket locks available to retrofit onto them?
Not that I'm aware of.
Some owners have installed shoulder belts with pre 68 seats, just like some defeat the sheer pins in steering column shafts, etc... They know and ignore the safety issues.
"I aint gonna wreck it anyway" mentality belongs to real human beans.
The crash test dummies don't know they are in for a bad day every day. LOL