I have some cut off steering arms. You could cut the end of the pitman arm off and weld on a boss from an arm with the hole in it. That is what I did with the exact same problem you have. All the parts would be Henry steel and it welds beautifully.
I would send you a boss for shipping cost.
PS I have an A steering arm. Great shape. I would take $10 for it plus shipping. You could have it welded up and not modify the arm you have.
