G'day.
Colombian authorities only publish reports from 1995 and further, so I asked them for some more reports from plane crashes in the past:
I had uploaded these: https://www.reddit.com/r/aircrashinvestigation/comments/1rt0ngo/report_of_colombian_plane_crashes/
And I put the ones I've just got in the same Drive folder: https://drive.google.com/drive/folders/1uuggyGIgkGRxIz7Tl3Uupsse__mqJoPu?usp=sharing
The new ones are:
Avianca Flight 4, (DC-4 HK-730) near Cartagena, on January 14th, 1966
https://aviation-safety.net/asndb/332453
Aerocondor flight 139, L-188A (HK-777) crash at the Cerro El Cable in Bogotá, August 17th, 1973
https://aviation-safety.net/wikibase/330108
Aerolíneas TAO flight 514 (Vickers Viscount HK-1058) on June 8th, 1974, crash near Cúcuta
https://aviation-safety.net/wikibase/329890
On January 23rd, 1985, there were two events barely 20 minutes one after the other...
AIRES flight 584, (EMB-110 HK-2638) near Buga
https://aviation-safety.net/asndb/type/E110
ACES flight 52 (DHC-6 HK-1910) near Salgar.
https://aviation-safety.net/wikibase/327272
Avianca flight 410, (B727 HK-1716) near Cúcuta, March 17th, 1988, which is in the ICAO Aircraft Accident Digests, but this one is the original.