Whether it was a old transaction or new i.e., prior to the said judgment or after that, the law states that the title to the buyer of the property can be conferred only by a registered sale deed or gift deed etc.
The sale agreement is not a deed which will enable your husband to acquire the title to the property neither the GPA deed.
If the property was bequeathed to him by the testator then he should have enforced the Will by following the procedures i.e., by mutating the property to his name through transfer of revenue and other records to his name.
If he has not done these acts, then it can be termed that he has not acted upon the Will.
Therefore as per law the property still remains with the original owner.
On the basis of the sale consideration paid in full at that time and being in possession of the property ever since, as a legal heir you can demand the original owner or his legal heirs if the original owner is reported to have died to execute a registered sale deed to your name, failing which you can file a suit for specific relief before a court competent seeking direction to the opposite party to register the property to your name on the basis of the documentary evidences in your support.