Ah yes, I'd glanced atthat but dismissed the 'half a deckplan' but it would make a goodcruiser if the plans were completed - a fun project 
Just checked it - its the Type AT, the 'Prosperity'.

Just checked it - its the Type AT, the 'Prosperity'.
You could do it with a stock Type MT (deck plans from the CT Alien Realms supplement) flagged as a Naval Auxiliary -- but she's a Jump-4 hull, which eliminates some of your navigation challenges.
Alternatively, you could go with a Jump-2 1000-dton Solomani Type SK (no deckplans available, but you could rescale & repurpose the MT ones above since much of it is off-map cargo & fuel) and simply decide she is a prize taken from the Sword Worlds in the 5FW and now operating as an Auxiliary in private hands under the ownership of a former IN line officer...