>>20613
I've satisfied some of that desire after finding a first-hand account by Muricy narrating his march.
Some things I've realized:

-Trade unions were a net asset to the right-wing. They declared a nationwide strike but it only properly took place in Guanabara and Rio de Janeiro, preventing the mobilization of militants from the suburbs to the city center and not interferring with the rebel states. I've found one source claiming fifth-column activity but the call was for a general strike, it didn't go far (though it did reach Santos in São Paulo) because of limited communications. It's also worth noting Minas Gerais began its wave of leftist arrests early on so it was in no condition to be hampered by a strike.
-Common soldiers in the legalist side had no idea what they were doing and some thought it was an exercise or a civil disorder.
-The problem of military indiscipline transcended ideology -indeed, the right's conspiracies were part of it- and continued unabated once the right took over and purged the left from the institution.
-Whoever won, the normal democratic order was no longer in place at least in the immediate future. Both legalists and rebels censored the media, one oppositionist newspaper had marines waving their guns inside its offices and wasn't allowed to circulate. Goulart would have to name appointed governors for several states.
-As soon as the 'revolution' was victorious everyone tried to claim responsibility for it.
-Goulart was in 3 different occasions over the coup offered to break with the left and win over the military. It was the same decision as in 1961, it was his political agenda and not his person that was the concern.

I've got sufficient sources to map one of the battles that almost took place. At night in the 31st Kruel was in conference with his officers while Zerbini ordered the troops in the Paraíba valley into recon missions towards the rebellion in Minas Gerais. He was promised reinforcements, the general Anfrísio da Rocha Lima's School-Unit Group, the Army's only fully staffed, equipped and trained unit. In 23:00-00:00 Kruel exchanged his last words with the President, demanding him to part ways with the left. Goulart answered that he was lonely and isolated and couldn't abandon the only allies he had, and then said "Put your troops in the streets and betray me openly" which he promptly did.
Through dawn authority slipped out of Zerbini's fingers and forces in the Paraíba valley joined up with the rest of the IInd Army on an eastward march to Rio de Janeiro through the Dutra highway. Anfrísio's forces were still coming on the same route westwards, packing up in the morning, and the two were on a collision course.
In the middle of the road in Resende was Agulhas Negras, the Military Academy, which any civilian can name. It was under Emílio Garrastazu Médici, future hardliner President who'd witness the apex of the military regime. Médici was part of the Ist Army but sided with the IInd, mobilized his cadets and entrenched them on the road.