I just found this letter written by Southern Winds' Cristian Maggio, containing A4's fleet growth plans. It mentions the leasing of two 747-200s, confirming a rumour that had been going around for some months. They are supposed to have picked two British RR-powered 747-200s. I doubt those are from EAC, and would rather guess them to be ex-VS -219B, since they are quite young (82/83) and should have PTVs throughout the plane such as to compete with AR and IB on the same route, which offer superior equipment I'd say.
Here is the link for the complete letter, in Spanish (PDF format):