for exact replacement, you may need to go to Ford. go in person, tell them what you need, year of truck etc, they can look it up on their system and they might even have them in stock. (take your old ones to compare) I had to do this for the stupid plastic clips for the tailgate handle on my 97 because all the auto parts stortes did not have anything that worked. some were close but still didn't work. you might be surprised at how cheap OEM Ford hardware might be, it cost me 11 bucks for two new plastic clips, made by ford. I can't imagine those being that much.
As for stripped, your clips may have also been aftermarket (maybe the previous owner needed to replace them and found a Dorman version and they were a so-so fit and now you are dealing with the fall out. give Ford a try.
AJ