Not positive these are original but there are 4 small (1/8" ?) matching screw holes for the bottoms of the bumpers and the measurements are symmetrical.
Photo 1
These two are both 1 inch forward of the vertical fresh air vent control rods in the fenders.
And there are another pair of matching holes 21 inches forward of these two.
Photo 2, close up, drivers side. Showing the fresh air vent rod (arrow) and the screw hole for the rubber bumper (red circle).
Here's a google search link to more than a few photos of much nicer looking engine compartments.
Most of them show the hood bumpers along the outer edges...
https://www.google.com/search?q=imag...=firefox-b-1-d
.