OK, this is a first design under MgT for me, so comments and constructive critique welcome 
I was thinking that the usual 'bog-standard' ships that PCs tend to blunder about in fall into one of three main designs: Free trader, Far Trader, and Subsidised (Fat) Trader. That's not much choice, with nothing between the 200 and 400 ton options. There have been a few 300-ton jobs knocking around, but they never really took my attention, Then I got to thinking; if they can IRL make shortened and stretched versions of the Boeing 747, why not starships in Traveller?
"Ladies and gentlemen, we present to you the prototype of the Product-Improved Type AB-300 Free Trader. LSP has stretched the body to increase capability, improved performance with a Jump-2 capability, beefed up the crew and passenger complement, and still designed a ship that can be a decent workhorse in the Tramp Freight community, while incorporating all the new safety requirements that the Imperial Aerospace Authority requires on new-build starships (survival pods, in short!)"
Basically, it's a speculative cargo ship, slightly under-cargo, but still (I think) capable of turning a reasonably intelligent profit. For those places that are a bit out of the way and ever so slightly dodgy, the current (PC) owner has managed to upgrade the avionics to include a military package.
Comments, observations, and suggestions welcome

I was thinking that the usual 'bog-standard' ships that PCs tend to blunder about in fall into one of three main designs: Free trader, Far Trader, and Subsidised (Fat) Trader. That's not much choice, with nothing between the 200 and 400 ton options. There have been a few 300-ton jobs knocking around, but they never really took my attention, Then I got to thinking; if they can IRL make shortened and stretched versions of the Boeing 747, why not starships in Traveller?
"Ladies and gentlemen, we present to you the prototype of the Product-Improved Type AB-300 Free Trader. LSP has stretched the body to increase capability, improved performance with a Jump-2 capability, beefed up the crew and passenger complement, and still designed a ship that can be a decent workhorse in the Tramp Freight community, while incorporating all the new safety requirements that the Imperial Aerospace Authority requires on new-build starships (survival pods, in short!)"
Basically, it's a speculative cargo ship, slightly under-cargo, but still (I think) capable of turning a reasonably intelligent profit. For those places that are a bit out of the way and ever so slightly dodgy, the current (PC) owner has managed to upgrade the avionics to include a military package.
Comments, observations, and suggestions welcome

Code:
Stretched Free Trader, class AB-300
Tons Price (Cr)
Hull 300 tons Hull 6 13,200,000
Streamlined Structure 6
Armour Crystaliron 8 points 30 5,280,000
Jump Drive C Jump 2 20 30,000,000
Manoeuvre Drive C Thrust 2 5 12,000,000
Power Plant C 10 24,000,000
Bridge 20 1,500,000
Computer Model 3 bis/fib Rating 15 (20 for Jump control) 4,000,000
Electronics Basic Military DM +0 2 100,000
Weapons Hardpoint #1 Triple Turret (Sandcaster/Particle Weapon/Missile Rack) 1 5,000,000
Hardpoint #2 Triple Turret (Sandcaster/Particle Weapon/Missile Rack) 1 5,000,000
Hardpoint #3 Triple Turret (Sandcaster/Particle Weapon/Missile Rack) 1 5,000,000
Fuel 36 tons, sufficient for one jump-2 and two weeks of operations 36
Cargo 82 tons 82
Staterooms etc
8 x Crew staterooms, 32 4,000,000
8 High/Mid passenger Staterooms 32 4,000,000
10 x Low berths 5 500,000
Crew: Pilot (Captain)
Navigator (Astrogator)
Engineer
Gunner / Cargo Hand
Gunner / Cargo Hand
Gunner / Cargo Hand
Medic
Steward
Extras 2 x Fuel Processors 2 10,000
Escape Pods x 16 8 1,600,000
Air/raft 4 275,000
Ship’s Locker
Luxuries package x 3 (DM +3 steward for passenger purposes) 3 300,000
ARSENAL - 36 x Smart Missiles (in 3 x Missile Rack reload crates) (1d6 damage) 3 90,000
ARSENAL - 60 x Sandcaster reloads (in 3 x crates of 20 barrels) 3 30,000
Software Manoeuvre / 0 Rating 0
Library / 0 Rating 0
Intellect Rating 10 1,000,000
Jump Control / 2 Rating 10 200,000
Evade / 2 Rating 15 2,000,000
Fire Control / 3 Rating 10 6,000,000
Auto Repair / 1 Rating 10 5,000,000
Maintenance Cost (Monthly) 130,085
Life Support Cost (Monthly) 33,000
Total tonnage and cost 300 130,085,000