Good eye. Sadly, the center adjusting nut on the right has actually been welded to the threads. 🤷♂️🤷♂️
The entire assembly appears to be fabricated, as many parts on our cars were.
with enough TLC I think one could use a Dremel cut off wheel to section-cut the welded nut enough to remove it, carefully file down the remaining welds and then re-tap??
I am down in Fresno and will gladly ship these up to you for no charge if you decide you can use them.
let me know,
Larry