Will (A): Wife formed in May 1993. It stated that all adopted or born children were to be included just as any other living children when the will was formed.
Will (B): Husband formed in June 1993. It stated that only "descendants" would be included in the distribution of the assets.
Husband passed away in June 1998. Wife took on the role as executor of half of his land and his home. The other half of his land and assets were placed in a trust (as according to his will).
Will (C): Wife formed in September of 1998. It stated that 1 son received the home, contents and 2 acres of land. She signed over the house deed into his name.
The son has not claimed this until after her death. He has not paid anything nor lived in the residence until now. It was unknown to all people besides the son.
It appears that Husband's Will has already been probated (well over 5 years ago), so that shouldn't be an issue anymore.
So, assuming that the Will that Wife executed in 1998 was valid, then it should be the will that is probated because it is her last will.
I'm not sure I understand why you provided quite as much detail as you did. The husband died in 1998 and his wife served as executor; his testamentary scheme was to leave her "half of his land and his home." I'm not sure if you are suggesting that the entire home or just half of it. I am similarly not sure whether the "land" you refer to the land on which the "home" stands or whether you are referring to multiple parcels of real property, at least one of which had a home on it.
Thereafter, the wife changed her will. You indicate that during her lifetime, the wife signed over the deed to the house to her son. By this, I suspect you mean that she named him as a joint tenant with right of survivorship, rather than an outright conveyance. That being the case, it would appear that the son became entitled to the house upon his mother's death, unless half of the interest in the home remained in trust.
Good luck to you.
Michael S. Haber is a New York attorney. As such, his responses to posted inquiries, such as the one above, are limited to his understanding of law in the jurisdiction in which he practices and not to any other jurisdiction. In addition, no response to any posted inquiry should be deemed to constitute legal advice, nor to constitute the existence of an attorney/client or other contractual or fiduciary relationship, inasmuch as rendering legal advice involves the ability of the attorney to ask appropriate questions of the person seeking such advice and to thus gather appropriate information. In addition, an attorney/client relationship is formed only by specific agreement. The purpose of this answer is to provide the questioner with general information, not to outline specific legal rights and remedies.