Cherry bomb,
Unfortunately, this is a first for me. I do have a recommendation from a friend and that is: use a tapered pivot pin to align and set the first hammer then drive through and center the other pin. Then drive out the tapered pin with the "real" pivot pin.
I know from experience that good advice, a lot of patience and going slowly will usually get the job done.
In addition, I know from experience that asking questions on this
site will usually result in finding a great solution. The members
are very helpful, knowledgeable and caring--a great group to have for support.
FOX SXS