I’m hoping that’s not it. In the past when I’ve had trouble getting the caliper pins out, they were ok from the beginning of the boot on “down” (in). Granted that I’ve never worked on a Ford B4, and I never had this much trouble, working on getting to the brake pads...
If it is like my Ranger, all the rubber parts are sold at the parts store. Confirm for your app and heat away. Also, if similar, the replacement caliper assy reuses the portion that bolts to the car and the pins are threaded into. I got the pins out through heat and bumping with an impact followed by a cheater bar application every 5 min until they moved. In my case the pins were reusable. Antisieze is your friend once you get it apart. Good luck