Start with the quality: the quality is determined by either the Mission Control or the interception. however if the space politics is Anti-nuke that overrides the spacecraft quality until enough off-world factories are built. Once you get one factory you get an ET produced spacecraft instead; 2 gives you an advanced spacecraft.
Medium quality spacecraft will either be generated the same as high quality spacecraft with some specific components down-graded, or as specific medium quality types — inner or outer system. Low quality spacecraft are even worse. Because of this, a step by step guide would end up having as many different paths as each possible combination of spacecraft qualities effectively doubling the length of the rules.
I’ve held off providing examples until I’ve got all the rules locked down. As the game is still in development that means there may not be examples for some time.