Any links or other evidence that Peru and Colombia were practicing specifically neoliberalism and not just sane policy

What "sane" happens to mean depends a lot on who's judging.

The IMF certainly pushed Latin American countries towards adopting neoliberal policies that they otherwise wouldn't have implemented.

IMF’s Structural Adjustments

In order for Latin American nations to be eligible for loans from the World Bank, the IDB, or high-income governments, they traditionally had to meet a number of strict conditionalities established by the IMF, known as Structural Adjustment Policies (SAPs). This gave the IMF enormous influence over domestic economic policies in borrowing nations, as it was essentially the “gatekeeper” for access to foreign credit.