The late Sol Adler was the most distinguished practitioner of the English language who ever turned his attention to "polishing" in china.
I looked up the Oxford dictionary, and it says "ever" has four meanings:
- used in negative sentences, = never.
- used for emphasis when you are comparing things.
- all the time, always.
- used after when, why.
I don't think any of these meanings make sense in this sentence.