Re: power steering pump
Have you tried removing it and taking it some place like NAPA? Often times there are equivalent parts that can be sourced and having the part in hand makes it easier to identify. Also, a parts place might be able to recommend a rebuild shop.
I think my '91 gasser has the same pump. I suspect a lot of the old farm trucks around here have one quite similar. Unfortunately, my '91 is spoken for after I'm done with it, so I can't offer parts.