The common assumption is that Chris couldn't find any rhyme or reason to the earlier stats. But JumpShips were pretty easy to figure out, so I think it's equally likely that he found the system and decided to change it.
DropShips are harder. (One confounding factor is that transit thrust seems to be independent of combat thrust.) I took a break from working them out to do some astrography; unfortunately, that was interrupted, and all such endeavors remain disrupted for me through the present. I hope to resume normal activity in a few weeks.
Notes about DS&JS:
- Bridge mass of the Scout, Invader and Star Lord round up to nearest whole ton. (The Star Lord entry accidentally copied its bridge mass from the Invader's entry.)
- The Scout's Bridge was calculated for a 79,000 ton ship, its engine for an 80,400 ton ship. [Edit: alternatively, its engine is a typo (1930 tons for 1920 tons) for an 80,000 ton ship.]
- The Merchant's KF mass was given as 11,000 tons instead of 110,000 tons. (A zero was left off the end.)
- The Invader was listed as 152,000 tons but its bridge and engine were calculated for 153,000 tons.
- The Star Lord was listed as 274,000 tons but its bridge and engine were calculated for 275,000 tons.
- The Monolith was given as 380,000 tons but its bridge and engine were calculated for 370,000 tons.
