In my 300mm V-Core 3.1 the DIN rails would not align well using the original mounts. The DIN rail would also be in front of the hole for the heater bed wires.
I've moved all din rails down by 50mm. I'm using half of a DIN rail wire guide at the top and bottom to complete the wire guide.
This way the DIN rails align pretty close to the panel mounting holes. I've made the bracket straight and added 4 holes so it will align with the panel mounting holes in all 3 positions. See my pictures for some more details.
For mounting use DIN912 M6x20mm screws with a washer.
The author remixed this model.
Changed the mounting to the frame so it works better in the 300mm VCore3.