" BECAUSE HE KNEW NOTHING ABOUT IT" - NO NEED TO SHOUT ;)
1. What has 'could not read' have to do with it? In Cymraeg, the two names are pronounced very differently(especially in the North).
2. "if they existed, they would have died at least 500 years before his time" Don't understand your point? Why is there a 500 year gap?
3. Have not read any baby name books!
4. "and your father, and his father". It's grandfather to grand son.
5. "Unless your family tradition of Aluns goes back a thousand years (unlikely)". So if I was able to show you my family (Llywarch) tree back to the year 1004, and show you all the Alun-s, you might belive me?
6. "Welsh and Brittonic are two similar languages, but they are not interchangeable" Sorry, might have to explain this one to me also. Being Cymraeg first language, I am able to read and understand 80% of all Brythoneg litrature I have read.
7. Sorry, just remembered, I have read a book on baby names, but it wasn't a Welsh one :)