I have been having trouble finding Heuers that I knew should be there in various record indexes. Then I recalled someone sending me a census record with a wild misspelling of the name and tried that - it worked!

The problem becomes a transcription problem compounded by lack of knowledge of German names.

In a lot of older handwriting the "u" and "n" are practically indistinguishable. If then a person not familiar with German names looks at this it is more likely to be transcribed as "Hener" than as "Heuer".

I found many of my Heuers in the census by looking up "Hener".