I compiled a JSON index of all the tracks from various sources. The site loads the index and calls the YouTube API to find the best match video. Simples! I manually blacklisted and whitelisted some video ids as reports of missing/broken tracks came in last year, but it's pretty robust as videos come and go.
What does the site actually do? Did you have to find all the tracks manually on Youtube? Were they all findable? What happens if they disappear?