Question about copying a spacecraft artifact creature

Ran into a moment with some artifact/creature copying that we couldn't figure it out. Would love to get some clarity if you have thoughts: Opponent has Hearthhull, the Worldseed, it has 8 station counters, making it an artifact creature (6/7 with flying, vigilance, and haste). I play Imposter Mech and choose to make it a copy of that creature, assuming it will copy the 6/7 creature portion (ignoring the pre-creature state before it was stationed). So now to me I have a vehicle artifact that is 6/7 with flying, vigilance, and haste. Am I correct here, or does the spacecraft stuff invalidate my card from copying it as a creature?