A long time ago there was a DC8 flying into Quito, Ecuador that was saved by an early Generation GPWS. I don't have all the details but maybe with all your already done research you might be able to dig up some info. I believe it was in the early eighties. The crew began the VOR approach using the wrong VOR i.e. the descent was initiated too early. When the GPWS sounded the crew pushed the throttles to their mechanical stops and flew parallel to the mountain the RA indicating between 150 and 200 ft until they were clear of the mountain.
good luck with you report
efcop