[Psientist]

well, you could set variables in quests that give "component" ships to the player... and a quest that looks to see you have all the user variables set that are necessary (e.g., "head=true", "leftarm=true", "rightarm=true" etc) and gives a new ship when all are together...

But I don't think there is a quest command to REMOVE an existing ship from a player fleet, which would be necessary. i'm sure there's a way, but one of the game developers would have to share that.