I am so sorry for your loss and for your situation.  First, you need to hire an attorney that is not involved with this process at all.  And right away.  The attorney needs to contact your Father's attorney as to a copy of the original Will.  There is a process in every state for lost Wills and proving a copy as an original.  It is an arduous task but it can be done.  Now, they can not change the Will and if his attorney tries then he could be in big trouble.  Although I do not know the particulars about the estate and how the assets are held (i.e., with his wife), I do know that if the Will is lost and can not be proven you would inherit under the intestacy statute in the state.  Good luck to you.