This is a remix of the double doorway with bulkhead found here: https://www.thingiverse.com/thing:2609112
The changes has been made in order to make it fit Zone Mortalis terrain pieces from a well known UK manufacturer as well as fit thematically with Horus Heresy / 30K.
The extended slots on the sides has been removed, the bottom has been made a bit thinner and the aquila has been removed from the door.
To print properly the bulkhead should be scaled to about 92,5mm wide (height and thickness left alone). The door should then be scaled to the same percentage in the same axis. We also scaled the width and thickness of the door another 0.5mm after that to allow for paint without making the fit to tight.
If you do not wish to use this door with walls from the well known UK manufacturer you can of course leave the scale as is or scale it to any other dimensions you please.