This set is identical in make to the similar chess set I already posted some time ago, but with a major difference. The other set is merely identical to the pieces used in the 1979 Rio de Janeiro Interzonal chess tournament, while this set here is one of the sets actually used in the tournament, i.e. original pieces in the truest sense of the word. The chess pieces were offered to me by FM Alberto Mascarenhas, who played an active role in the tournament. As a close confidant of Henrique Mecking, Alberto, who was in his early 20s when the tournament was held, was invited to work as tournament staff and to operate a presentation board showing the moves of Mecking's games. After the tournament, Alberto's chess coach, Dijalma Baptista Caiafa, who was also involved in the organisation of the tournament, kept a set of the competition pieces after the end of the tournament, on which he played many private games at his home. After Caiafa's death, his widow donated the set to the local chess club ‘Associação Leopoldinense de Xadrez’ of which Mascarenhas is president

The pieces were manufactured by Bonatto & Cia. Ltda., a company based at Rua Dr. Goulin, 2351 in Curitiba in the state of Paraná, in the far south of Brazil. Bonatto was founded shortly after the Second World War, on 6 June 1946, and specialised in the manufacture of wooden articles. The chess pieces manufactured by Bonatto, of the type used in the Rio de Janeiro Interzonal Tournament, are made from local hardwood. The white side is coated with a clear varnish, while the dark side is lacquered black. The king size is 11.5 cm. All pieces are weighted with lead inserts. Bonatto chess pieces were always supplied with green felt bases. However, there is one special feature that only those directly involved in the tournament are aware of: for the 1979 Interzonal Tournament in Rio de Janeiro, Bonatto covered the small quantity of tournament pieces with orange- pink felt bases. In addition to all the valuable information I received from Alberto Mascarenhas about the origin of this set of pieces and the tournament, it is the orange-pink felt pads that identify the chessmen as an original tournament set of the 1979 Rio de Janeiro Interzonal chess Tournament and as a valuable piece of chess history.

The set came with the equally rare original tournament booklet. 

If you are interested in more background information on the tournament and the set, check out my article "When Collecting Meets Chess History - 
The 1979 Rio de Janeiro Interzonal Tournament Chess Set" published in the November 2025 issue of the Chess Collector magazine (the link to which is also included on my Articles & Publications site.