Post divorce. Can assets be revisited to see if it is divisible?

The answer to your question is generally no. Property division is final as of the date of the divorce and cannot be reopened or adjusted, unless you both were to agree. You could try an s. 806.07 motion to reopen the order or judgment, but  those motions are usually met with great resistance by the other side, and reluctance by the court due to wanting to keep judgments "final." Under s. 767.127, any asset  of a value of more than $500 that is either negligently or intentionally failed to be disclosed, the other party aggrieved at any time can file a petition to have a constructive trust set up on that particular asset. Gifts and inheritances are exempt from property division under Wisconsin law. While the income can be used for child support or maintenance, the "profit" would not be subject to property division. The increased value of an exempt asset may be considered divisible, if the appreciation of the asset was by active appreciation as opposed to passive appreciations. Market conditions that causes an exempt asset to increase in value, would not be subject to division. If by example, he inherited or was gifted a farm, and you both worked on the farm and built a new farm house, increased the number of cattle and saw the farm grow in value by mutual joint marital efforts, the increased value of the farm under my example would be considered a martial asset subject to division.