Do not right-click-save-as any of these, or you won't get the special glow sprites. Get the download further down.
Large Engine Room;

To suit my custom retooling of the Nisos/Fed Cruiser B and her nonstandard 2x/3y engine room. Slot should be #3, set to face right.
Small Drone Room;

Again another custom for the Nisos/FCB, 2x/1y drone room. Since I shuffled some rooms around I needed one that fit properly.
Small Life Support;

Simply another small life support option for smaller rooms/ships. I took #9 and rotated the end pieces through 180 degrees around the center, then layered them under the O2 tank.
Small Sensors;

It's sensor room 3, but rotated through 180 degrees (twice clockwise, rather than just flipped). Simple.
Small Weapons;

A custom weapons room used whilst I was settling on a proper option for the room sprite to use for the custom NIsos/FCB's shuffled arty room.
Extended Weapons;

As above, but one tile longer.
DOWNLOAD v1!
Just put all the files in img/ships/interior, then adjust the img="..." and room lines (such as slots and facings) in blueprints.xml appropriately. Nice and simple.
Feel free to post your own room interiors here if you've made any.