I love the quiz, but there are a couple of issues. First, the name of the album is "Houses of the Holy", not "House...". Second, "Hey Hey What Can I Do" was never released on Led Zeppelin III, to the best of my (and Wikipedia's) knowledge. It wasn't even released on Coda until many years later as an extended CD edition that was part of the compilation "Complete Studio Recordings". It was originally a B-side to the single for "The Immigrant Song". The first time that "Hey Hey" and "Travelling Riverside Blues" were released on an album was in the Led Zeppelin Box set in 1990.
Bron-Y-Aur was actually a typo on the original album, fixed in modern releases. I'll probably change the description to "original album releases" instead of including CD/online versions.
I must've been looking at my reissue of Led III, where Hey Hey was a bonus track. Fixed to go along with the original release.