The $5 stamp showing a Tracktor is from 2009 Mercosur Products for Export issue.
Mercosur (Southern Common Market) is a Regional Trade Agreement between Argentina, Brazil, Paraguay and Uruguay founded in 1991 by the Treaty of Asunción, which was later amended and updated by the 1994 Treaty of Ouro Preto. Its purpose is to promote free trade and the fluid movement of goods, people, and currency. The official languages are Portuguese and Spanish.
Mercosur origins trace back to 1985 when Presidents Raúl Alfonsín of Argentina and José Sarney of Brazil signed the Argentina-Brazil Integration and Economics Cooperation Program or PICE.The program also proposed the Gaucho as a currency for regional trade.
Bolivia, Chile, Colombia, Ecuador and Peru currently have associate member status. Venezuela signed a membership agreement on 17 June 2006, but before becoming a full member its entry has to be ratified by the Paraguayan parliament. The founding of the Mercosur Parliament was agreed at the December 2004 presidential summit. It should have 18 representatives from each country by 2010.Israel is currently the only non-South American free trade partner.
The $1 stamp in the middle was issued in 2009 commemorating 150th Anniversary of the Children of the Holy Virgin at the Orchard Congregation, in Argentina representing one of the apostolic work of the Congregation: teaching in schools. Downtown, San Antonio Maria Gianelli blessing to the sisters and students. The work belongs to the Congregation of the Daughters of Mary Garden.
The next $1 stamp was also issued in 2009 commemorating 100th Anniversary of Exaltation of the Holy Cross Parish in Santa Cruz showing view of the facade and detail of the stained glass of the main rosette.