In 1976 (adjacent Granma memorial inaugurated on December 1st, 1976) I practiced gymnastics on the floor above the Cuban national fencing team training facilities (national ballet school building in satellite photo).
I have names of Cubans (some on the Island (former United Nations representative for example), others in exile) directly involved in the operation.
Uniformed French policemen and military used the bombing for biometric measurements and biotechnology satellite attacks, photos and videos available.
Raul Castro Ruz implicated.
Below description taken from wikipedia:

Cubana Flight 455 was a Cubana flight from Barbados to Jamaica that was brought down by a terrorist attack on October 6, 1976. All 78 people on board the Douglas DC-8 aircraft were killed in what was then the most deadly terrorist airline attack in the Western hemisphere. Two time bombs were used, variously described as dynamite or C-4.
Evidence implicated several CIA-linked anti-Castro Cuban exiles and members of the Venezuelan secret police DISIP. Political complications quickly arose when Cuba accused the US government of being an accomplice to the attack. CIA documents released in 2005 indicate that the agency "had concrete advance intelligence, as early as June 1976, on plans by Cuban exile terrorist groups to bomb a Cubana airliner." Former CIA operative Posada Carriles denies involvement but provides many details of the incident in his book "Caminos del Guerrero" (Way of the Warrior).[1][2]
Four men were arrested in connection with the bombing and a trial was held in Venezuela: Freddy Lugo and Hernan Ricardo Lozano were sentenced to 20-year prison terms; Orlando Bosch was acquitted because of technical defects in the prosecution evidence, and lived in Miami, Florida until he died on the 27th of April, 2011; and Luis Posada Carriles was held for eight years while awaiting a final sentence, but eventually fled. He later entered the United States, where he was held on charges of entering the country illegally but released on April 19, 2007.