I don't know what manufacturer makes these, but there is an expat who swears by them and helps bike tourists buy them (or any other bike).
http://www.horizonsunlimited.com/hub...get-ride-76478
Maybe you know the guy? One of the Peruvian brands is Ronco. On another Chinese-bike-oriented website, the sales rep for the nanufacturer Bashan chimed in. I PM'd him to see who they (local brands) OEM in Mexico, Central, and South America, and he gave me several brands. However, for Peru, he didn't give me brands, but rather said they 'have almost 15 distributors all over the country, everyone knows Bashan'.
Of course, these are bikes that are competing with the 'lower end' Zongshen models, not the RX3. I think it is fuel tank size you are looking for in a 'basic' bike, or being able to upgrade. Maybe the guy on Horizonsunlimited could help you in this regard since he is involved with motorcycle mechanics?