Around the issue #18 mark, Shckwave stated that he had built a spacebridge while also working on Megatron, thats how Starscream was able to get to earth to beat up Thundercracker, and I assumed how Megatron and company got to earth (to catch Prime and all hat humdrum). Problem was it ws inaccurate as they had no bridge exit point on earth, so they could only approx into earth orbit.
Having Megatron as the exit point bridge, guess it is alot more accurate.
I guess Soundwaves damage was easy to fix, maybe they picked up some cybertronian metal while on earth? 
Science bots for techno-babble led deus ex machina finish? Maybe a rebuilt Kimia?
Looking For: Wreckers Saga TPB Collection (with Requiem)