Such further allowances may be made as the court deems just and reasonable for any extraordinary services, such as:
1. Management, sales or mortgages of real or personal property.
2. Contested or litigated claims against the estate.
3. The adjustment and payments of extensive or complicated estate taxes.
4. Litigation in regard to the property of the estate.
5. The carrying on of the decedent’s business pursuant to an order of the court.
6. Such other litigation or special services as may be necessary for the personal representative to prosecute, defend or perform.