I'm afraid I can't tell you where but in Essentials: Online, there is some code that should help you with the connecting maps. It took me a very long time to figure out how to get them to redisplay after Netplay's code broke them so I don't suggest trying to figure it out from scratch.
In fact, check out lines 563 to 580 in Essentials: Online. Those are some (if not all) of the modifications I made. From what I can see, some of the definitions in Game_Map were replaced by Netplay functions - I assume it should be the same case in mode 7 (it was back when I tried to port it myself, never finished it though).