All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
As regards the expenses of the inheritance distribution stated in the above question, they are the liability of every heir; each according to their share in the inheritance. For example, the heir who gets (20%) from the inheritance must pay (20%) of the inheritance expenses and the like.
As for the efforts that you have made and the fees you have paid, this can be assessed by experts in this field and you can ask the heirs to pay for that if you did what you did based on their direct request since doing it voluntarily makes you entitled for nothing. However, if they decided to give you any amount on voluntary basis, then you can take it. And Allah The Almighty Knows Best.