From someone who's restored hundreds of Pantera-Girling calipers in the past, a few tips. First, do NOT split the front caliper halves unless absolutely necessary. The two halves are sealed with a hard-to-find and unbelievably expensive square Viton o-ring. Round ones of the same size WILL NOT WORK. That o-ring is NOT in the rebuild kits You'll also need a torque wrench and a metric allen socket to bolt the halves together again.
Next, the white nylon sliding parts in the rear calipers are now quite brittle so handle/stress them as little as possible. While the rear calipers are 'easier' to rebuild, almost all the parts are left or right hand mirror images and cannot be swapped from side to side. So it's incredibly easy to wind up with a set of four perfectly home-rebuilt brakes that are missing one, little bitty piece for just one brake..... that is unavailable.
Frozen bleeder screws (from apparently NEVER having been bled?) snap off an inch inside castings during removal and almost cannot be drilled out without buggering up the needle seats. I used a precision milling machine and still lost a few caliper halves. I also used gallons of Knock-em-Loose penetrating oil, not some home-made mix, and very high quality U.S-made 1/4" hex sockets on stuck bleeder screws, NOT Vice-grips or tiny open end wrenches. And I also used real U.S-made metric line-wrenches, often with Vice-grips clamped across the line wrench jaws. Because even high quality line wrench jaws in this size will open enough under removal torque to round off the soft metric hydraulic fittings. There are more gotcha's in restoring these overstressed 50-yr old safety parts.
And if all seems lost and your car still needs brakes, you have two (2.0) further choices. Either substitute an aftermarket caliper kit (which are better and half the weight), or call Larry Stock at PanteraParts.com who rebuilds Pantera/Girling calipers. He will (mostly) take your filthy OEM parts as cores if not broken, and sell you nice clean pro-rebuilt Girlings reasonably priced, with all missing pieces restored including NEW caliper lines & fittings. Its nice to have choices- good luck.