Hello! Sorry for digging up an old thread, but would like to add my experience for anyone coming across this while researching.

I have a leak at the exact same spot, same car (1997 960, 177K). The fuel line connector with the O-ring was very loose in the fuel rail- I could easily pull it out with my fingers. I'm replacing the O-ring and installing rebuilt injectors (phenolic rings on the manifold side of the original injectors are brittle and cracking). I'll update when the parts arrive and I get everything back together.

Oh- also replaced the spark plugs, which showed a definite lean condition (powdery white tips). No codes, but probably not good for longevity. My guess is reduced fuel pressure from said leak is causing it.