There are more "cargo spaces" than indicated in most of the "official" wright ups.
For one, even though head room becomes an issue, the upper gallery is always a great storage space. This area in most official write-ups is used for mission specific equipment; listing devises, long range sensors, survey equipment, etc... Once the ship is mothballed until a P.C. comes along, all this specialized equipment is stripped. There is also the lower hold accessible only from the underside of the hull, used for extra storage like survival gear or even a portable shelter for extend "on world" missions.
In any case, just making a point that there is a lot more available cargo area. When I first started roll playing traveller back in the "good old days", 83-85, I once crammed almost 30 tons of cargo into every nook and cranny.
I have to admit, I have never known of a rule which prohibits scouts from earning a living by carrying cargo or a couple of passengers.
Anyone can charter the use of the ship. Include some of there personal baggage and supplies for an extended geological survey, etc...
Just one more note. The campaign that I am planning will include an old scout that has "modifications". This has passed from one captain to another over the years, each one adding their own personal touch.
The upper galley will have overhead cargo doors. Originally these door were installed to launch probes and to deploy large antenna. The doors just happen to be large enough for an air raft to pass down into the galley. This makes loading and unloading cargo a snap.
The small room that's generally considered cargo space, will have a hatch identical to the airraft bay, again for easy loading/unloading, and the air raft bay itself will include (believe it or not) a small airlock!
I'm even thinking about putting ejector seats in the bridge just mess with my P.C.s!
To offset these little "perks" some systems of this old scout can at times be cantankerous... at G.M.s options of course...
In Far Trader, there is a practice encouraged for players to send advertisements via xboats or other vessels to ports that the characters plan to visit. "Suliman Scout currier in route to Glisten Sub sector. Arrival at down port on or around date (****). One sate room and 15 tons cargo space available. Any persons interested please post on message board." or something of that nature.
A character with a scout currier can carry messages such as these for other liners, or companies. You can make a little spending cash and not take up a square centimeter of cargo space.
With a good imaginations, characters can find hundreds of ways to make money with the good old reliable scout courier. It's one of the best "adventurer" ships in my book.
Jaknaz