This is resository is contains a Blender3d add-on that adds a menu item in the File > Export called Blockbuster JSON. With this add-on you can easily setup a Blockbuster mod custom model when exporting the OBJ file.

Download this as zip, then in Blender's add-ons panel (File > User Preferences > Add-ons), click Install from File... and finally choose the downloaded zip. That should install this exporter script.

Note: this script was written for Blender 2.78.

Once you exported the OBJ/MTL file, you can use this add-ons' File > Export > Blockbuster JSON (.json) menu item to generate a JSON file with configured origin and default poses. Simply repeat same steps to export the OBJ file, but with this exporter, reload models in Blockbuster mod (by either pressing B key or /model reload, and it should work out).