Guessing you have at least a spring 66 built car or even later. Here are some general shots of originals. It should be mentioned that not all cars got a bare spot around the trunk interior holes that was visible with the rubber plugs in place but the more typical hold downs that screwed into the pedestals from above and held the car to the fixture were visible. Seems there were two sized large washers used for some reason though both deformed the trunk floors slightly or move around those mounting holes
A few examples though suggest you and others interested in the subject do read the resources I provided above
Rear most

And from above in the trunk

Near the front mounting point for the rear spring

Near rear end of the front frame rail that attaches to the forward main floor panel

And from above in the interior

Don't have any clear picture of the forward ones at the front #1 cross member. Typically this are sees allot of surface damage so coatings are often gone plus red oxide is
sometimes not sprayed (read missed) on those surfaces. When found they are the same size and shape as the others