I hope I blow your mind on this one because I'm a very lucky man. If own a new Mach 1 you have pictures of my Mach 1 1969. If do a web search at Bill Musser at Ford Performance you see article about me. Bill Musser's 1969 Mach 1 (ford.com)
Just replace all the plastic push pins on front splitter. Put threaded rivets in and put 1/4 x 20 bolts stainless steel. I have two front splitters and I have a new one and I use when it’s scraped up a little so I like to switch them back-and-forth.