That's fascinating. It never occurred to me that the samples listed in Book 2 were basically the ship designs.
And a question: You got to the 12,000 ton ship by extrapolating the table out from the 4,000 ton hull. But, as you point out, performance starts dropping at 2,000. Is it possible there is another large drop in performance above 5,000 tons?
I really never played around with the ship combat much at all, so seeing how the performance drops so steeply after 2,000 tons is a big insight into how the game is balance toward the smaller ships.
THe Bk2 stock designs aren't "THE designs."... there's room for some variety.
But there are some interesting hiccups... note that the performance by pure book 2 is due to drive letter limitations, and artificially lowering the performance of drives W-Z in 1000-3000Td hulls from what would be formulaic.
And some interesting tidbits about hulls and TL's at which they happen...
J3 is available at TL9. J4 at TL 10. J5 at TL 13, and J6 at TL 14 or 15... but only in specific hulls.
It makes a huge difference in how the setting works when TL9 has J3 performance.
Also, under Bk2-'77 you can use a 1/bis for any jump distance.
You may want to change prices for freight to Cr1000 per parsec, not per jump; if you do, there are hulls that can turn a profit (on pure cargo designs) to J6, assuming they fill.
CT-81, those hulls:
J1, J2: 200, 400, 600, 800, 1000, 2000, 3000, 4000, 5000
J3: 400, 600, 800, 1000, 2000, 3000, 4000
J4: 800, 1000, 2000, 3000
J5, J6: 2000
CT 77, those hulls
J1, J2: 200, 400, 600, 800, 1000, 2000, 3000, 4000, 5000
J3: 200, 400, 600, 800, 1000, 2000, 3000, 4000
J4: 400, 600, 800, 1000, 2000, 3000
J5: 800, 1000, 2000
J6: 2000
And, hulls are effectively limited by TL
TL 9: 100-800
TL 10: 1000
TL 11: 2000
TL 13: 3000
TL 15: 5000