Since we did not see Tomo at the end with Steve Martin, I guess we could assume he was killed during Godzilla's rampage (which is sad, since I always liked Tomo).
In seeing this again recently, both Terry Morse and Terry Morse, Jr did a great job in editing this. I would think it is not easy splicing two movies together and making it a winner, but they managed to do it.
And I wonder if there was this big brouhaha in 1955-56 over lack of a trailer for this one.