I'm somewhat skeptical that the EC/ Charlton relationship continued very long, since most reports claim the reason for the later printing of Impact #1 was because Gaines felt the printing on the Charlton version was too poor to release, particularly on "Master Race". My copy of the issue is the Yellow logo version.
Still, interesting discoveries.
I was skeptical also, but the industry was in a tailspin at the time. With EC comics not getting displayed at many locations, Charlton's distribution network may have given them a better shot. Again, I'm just speculating because strange facts are coming out of that era and they don't fit together as easily as they should.
Max Gaines and his family had some connection to Connecticut. Evidently, the Bridgeport Herald published his newspaper inserts...
http://comiclist.comuf.com/EC/Picture_Stories_From_the_Bible/PSFTB_OT_Sunday_Herald.htmland people were claiming Max Gaines was involved with the publication of Picture News & The Gumps with that newspaper. The company formed to publish those ceased to exist around the time Max Gaines died. Marie Severin said that in the 50's, color separations were done in Bridgeport.
According to Google maps, Bridgeport & Derby are only 15 minutes apart from one another.
Charlton was gobbling up many of the publishers that were struggling in the 50's. Then the floods crippled them.
I'm not sure if there are any strings tying all of that together, but I suspect there are. Charlton may have negotiating to buy EC like they'd done with many other publishers.
The floods along with the success of Mad magazine could have been what prevented it.