AA: MXP-GRU $3044 ai RT 11.6 cpm (22620 eqp - 7 nights required)
Not an MR due to the 7-day stay in GRU, but a pretty good deal...
MXP-JFK-GRU-JFK-MXP, with the JFK-GRU-JFK on the 77W.
Can also route MXP-LHR-JFK-GRU-JFK-LHR-MXP for about $100 more and can get the 77W from LHR-JFK-GRU-JFK.
Sample date:
Leave April 5 return April 16
Availability throughout EOS.
(I found this after seeing the economy variation under the MR forum.)