Anyone out there have details/photos of seat belt locations on a 57 Belvedere 4 door sedan ?

[58Belvedere]

Mounting kit Seat Belt Mounting Kit, Retrofit Kit, Reinforcement Plates Plus Shoulder Bolts | eBay

 

[58Belvedere]

Yellow zinc bolts: Seat Belt Harness Hardware Bolt Sleeved Shoulder Lap Mounting Bolt Washer Nut | eBay

 

[Sixpactogo]

My car is a 60 Dodge but I would think the factory would have provided the mounting dimples back in 57 also. I only added the front belts in my car and did not check for the dimples for the rear mounts. I bought a set of aftermarket belts that came with the backing plates and hardware. Here are a few pics showing the factory dimples and where they were located on my car. Should be similar in 57. They should be found just to the rear of lower seat cushion when all the way back.