Donor and three half brothers found.
I found the first half brother here on DSR. To be sure, his mother had me do the DNA through 23andMe. Another half brother was confirmed on the DNA site. I discovered another half brother on GEDmatch.com. That makes three half siblings with the same donor. I then started doing lots of research by contacting people on 23andMe and GEDmatch. I was told to transfer my son's DNA to FamilyTreeDNA. The first thing I did was make a list of close relatives and looked at the names they had mentioned. I saw the name Jensen mentioned in six out of seven names. I also used Facebook. I was able to find the sister of a second cousin on 23andMe. A son of another second cousin also helped me by naming his connection to the Jensen line. I connected them back to the same great grand parents. I worked from there forwards. I was able to find who I thought was my son's great great grandmother but I had the wrong person. It was her sister I needed to follow. I had been reading a LOT of obituaries. I also looked on Find A Grave and they had some obituaries. I was able to find the donor this way. It took me two years but I was able to call and speak to the donor. By speaking to him I was able to give the guys what they wanted: a picture, a name and medical history. He doesn't want contact with the donor children but was very nice to me. I do have some contact with one of his non donor sons in case another sibling shows up.