The FSM article used one kit. That usually is a factor of cost and availability of the kits, and how the cabin windows are created. Looks like yours are decals. I see that Embraer added two.
I'd try making a plug. I've done it both ways, and I've done one shortening, DC-6 to a DC-4.
As for where. You would need drawings, but it looks like they did it mostly forward. There are two extra windows between the bulge and the front cabin door. The space between the front window and the door looks like it got a little smaller.
I've done it both ways, and I've done one shortening, DC-6 to a DC-4.