Probably shouldn't buff them.
A good analog for the FDL's uniquely advantageous combination of attributes, except there aren't any exclusive CGs rewards that can make other ships broadly competitive (not that this is a good fix for anything).
I'd be ok with the T-9 and T-7 buffs being reverted as well. The problem was never that they couldn't carry enough cargo, or weren't durable enough. It was that the pseudoeconomy had been neglected too long (depreciating all of the reasons to use these cheaper vessels) and the game never provided any situations that taught traders the advantage of a small HRP.
"The game should teach you how to play the way I say. That's the problem, people can do what they want..."