@nern if the husband was the sole proprietor farmer through 2018, then he likely would have owned 100% of all of the farm machinery bought during 2018 and all prior years.

The husband would likely still have retained ownership of his farm machinery even after he was no longer operating the farm.  Even if the wife would have used his farm machinery to operate her farm, he likely would have retained ownership of his farm machinery.

In the 2019 transition year where she became the farm operator did they file two Schedule F's, one for him and one for her?  Is there any evidence, such as a Bill of Sale, that shows that the husband transferred the ownership of all of his farm machinery to the wife prior to his demise?     

You need to get into contact with the attorney that handled the husband's estate as you seem to lack knowledge and understanding about the circumstances surrounding that event.