Does a Return of the Token Prices to Their Original Ratio Eliminate the Impermanent Loss?

Yes, if the ratio of the two token prices returns exactly to the ratio that existed at the moment the liquidity was deposited, the impermanent loss is fully eliminated. At this point, the value of the assets held in the pool would be exactly equal to the value of the assets if they had been simply held outside the pool.

This is the reason the loss is called "impermanent" ▴ it is unrealized and reversible.