The Type M Subsidized Merchant, also called the "Fat Trader", is one of the most common cargo carriers seen along single-jump space lanes. Many of these ships are "subsidized" to make regular runs between specific star systems to carry mail, staples, and specialized cargo. All deck plans are in 25mm scale.
Here are detailed deck plans for that 400 Ton shipping legend complete with the main cargo deck, passenger and crew deck, and a full exterior view of top. The 23 pages in this PDF includes the lower deck, upper deck, and the external view of the topside.
("Traveller" and the Traveller logo are Trademarks owned by Far Future Enterprises, Inc. and are used with permission. The Traveller Main Rulebook is available from Mongoose Publishing.)
Art from Cosmographer reproduced at floorplan-scale is with special permission from Profantasy Software Ltd.