The OEM plastic covers did not have them that I know off. It was later when it was determined that due to the heat on the plastic, they all bow, lift and leak....so a retro fit was used where two of the rocker bridges were replaced with ones having a threaded stud to allow downward force to help seat it better. (to me, it just makes the sides bow out more). The new cover didn't come with the stud bridges?
1975 CJ-6 1983 CJ-8
1986 CJ-7 Laredo 1986 TJ-7 Trail Jeep
2003 Inca Gold TJ Rubicon