Plenty of good advice here.
Only other idea I suggest is look for NOS or NORS on eBay. They got sold by a variety of vendors under a variety of part numbers in the distant past. Some people are leery of rubber in older parts, and there are certainly risks. I have found that rubber manufactured long ago is borderline eternal, whereas anything new-ish is almost guaranteed crap, right out of the box.
Your NOS pump will not be ethanol tolerant and will eventually fail with ethanol use. Then you just rebuild it with a kit from the aforementioned “Then and Now.”
