Odd find, hatch latch with 4 mounting bolts

[1rippen6]

I was removing a hatch latch and realized it had 4 mounting bolts so I'm wondering if it was a year thing like maybe 69? I also noticed the rod had dimples in it for lack of better terminology. I removed the hatch from a single wall top but it's the only one I've ever seen with 4 mounting bolts. I've removed the mounting plates from the inside of the hatches before to replace and the ones with 3 mounting holes only have 3 nuts.