This comic is tied with Amazing Spider-Man #1 (that one also featured the Fantastic Four) as the first ever Marvel cross-over. Wonder how many times the Thing and Hulk have butted heads over the years? I imagine someone out there has tried to document it. I will settle for many.
Eventually, I will have all FF V1 comics scanned front and back on my website. What I have so far can be found here: https://dekventures.com/FantasticFour/fantastic-four-v-1-regular-issues