OK -- I saw the Veterans headstone application info for Donald G. Pierce, so I'm assuming that's where you found his military info.
It's odd that his name doesn't come up in the WWII military records, though.
I think you should order his original Social Security application -- that should have his parents' names on it.
OR order his death certificate (you or someone else may have to prove a "direct" relationship, though...?)
http://www.health.pa.gov/MyRecords/Certificates/DeathCertifi...Here's a resource that I already tried: The Reading Eagle is free online at:
http://news.google.com/newspapers?nid=ZuSUVyMx-TgCI browsed the April 22 to April 30, 1975 obituaries and death notices, but found nothing re: Donald Pierce (which also seems odd to me.) One possibility: If he were well-known in the community, there may have been an article re: his death elsewhere in the paper. However, you'll need to scan hundreds of pages to find it! :(
Although Google claims that the pages can be searched, I've found that they really CAN'T, not accurately. The character-recognition just doesn't work all the time. Also, Google stopped maintaining the site years ago.