A rack of bottles (acetlyene, oxygen, etc.) for your 1/350th ship. These represent bottles racked up for use and/or storage. The rack wouls most likely be placed up against a wall or bulkhead. The rack itself might be wood or metal, so you may paint accordingly. You may wsh to use photoetch or super thin rigging line to simulate ropes or chains wrapping around these bottles, as they would normally be chained or roped down to keep them in place. In this scale, you just can't replicate that with the current technology as it would be interpreted as a "hanging wire" in several places and the design would not print. In time, this will hopefully change.