We are both catastrophe adjusters, the fuel line failure always occurred 100s or 1000s of miles away from shop performing the latest repair. The GM engine lower end overhaul was performed while former owner worked in Arizona. Fuel line was later replaced by Classic Cadillac in Atlanta months later. Independent mechanic shops performed multiple replacements. My 1st replacement as owner was performed by local auto repair shop. Shop discovered a weak motor mount after my suggestion to check while i was traveling out of state. Both fuel line & motor mount were replaced. As a former owner operator of a body shop, I performed my 2nd replacement. A total of 8,000? miles since my original owner replacement 2 additional lines have broke. The fuel line is part # 1259-1197 and is a rather simple repair.
That's not the most common part # for that fuel pipe. It took looking at google images after the search to finally see what you were referring to. That fuel pipe (as GM refers to it) is probably failing repeatedly because there is some degree of stress on it after install. When I replaced my high pressure pump, I realized the importance of a good finger snug tightness to all of the fuel fittings first, which would keep everything closely attached, but allow the ball and socket joints to pivot, as the pump and inlet fuel line retaining bolts were tightened.
If the pump is tightened down first and there is a little increase in its ideal distance from the injector rail resulting in that pipe being stretched on tightening, that maybe the cause, in which case the pump retaining bolts would need to be loosened (and replaced) for the next pipe, to insure there is no tension on it after install. Of course this is assuming the pipe is breaking as stated and not just leaking at the attached end.
If it is leaking repeatedly at either end, then you need to go ahead and replace the pump and the fuel rail it connects to, because the metal surfaces are probably damaged microscopically in a manner that will likely result in continued repeats, especially if that pipe has been replaced without the proper torque. I had to get pretty creative using a crow foot attachment to torque the end connected to the pump. One thing I rarely see mechanics use is a torque wrench.
GM is pretty sensitive about the fuel pipes which are one time use. The recommendation for a leak at either end of the pipe is replacement of the adjoining part along with the pipe to achieve undamaged mating surfaces.
Since your wife refuses to drive it, I'd say you're at the new fuel rails and pump stage to regain her confidence. If you agree, make sure it's done by the book which will include the need for new injector seals that require a special tool for proper installation.