I'm with 421dog on this.
Punting a 40+ year old 400 series Cessna in real ice (the type that starts before you even get airborne), poor visibilty and dodging storms with old tech radar (if any), basic autopilot (if it works at all), steam gauges (mostly working)
Fail to see how this is any different to any other GA job.
marginal engine-out performance
and you think a fully loaded 777 single engine out of Mexico City, Addis, or Kabul is any different? Again, fail to see your point.
Operators are not always keen to retrofit these old clunkers with the latest and greatest IFR gear, and even if they do, it's a bit like putting lipstick on a pig - the airframe, systems and performance are still a pig.
You obviously have never seen the inside of North Coast’s, at the time, P2-KAA!