Never let someone tell you there is no index or there is just one index to something. Determine if there is another index or if an index was created and published privately.
There were a series of land records I was searching for in a county in Illinois while at the Family History Library. They only had indexes to each volume, compiled separately in the front of each one.
What they did not have was another index to the land records that was created and maintained at the courthouse. That index had not been filmed and consequently was not at the Family History Library. Using that index took 5 minutes to find the deeds I needed. Going through the volumes’ indexes one-by-one would have taken me at least 3 hours.