What is permissible for this person to take from the money found in the curtain, and does he have the right to claim compensation from the owners of the money for damages he incurred, and is it permissible for him to take a compensatory amount by mutual agreement, and is it permissible for the mediator to take the difference between the lawyer's actual fee and the amount he reported to the owners of the money?

The owner of the money erred by burdening his neighbor with the tribulation of sending the amount, and he must bear the fine and lawyer's fees; because he is the cause and the aggressor. It is not permissible to compensate the neighbor for moral and psychological damage. It is not permissible to lie about the cost of legal fees. And if this resulted in the neighbor's imprisonment and loss of his job, then he must be compensated with a salary for the duration of his imprisonment, by analogy with compensating someone who was prevented from his craft due to a crime.