Locating Our Families Old World Origins with DNA

I've been buried deep in Haplogroup research since my cousin's DNA results came in last Friday. Eupedia has been the best resource for finding maps and explanations of the origins of Haplogroups. I've also been looking for test results posted by distant cousins of some of my other lines using the Family Tree DNA surname projects. I found a number of surname groups for family surnames at Family Tree DNA. I had forgotten how to see the results at first. I then remembered you have to use the menu in the bar near the top of the page. I also Googled to find more family surname projects. I managed to find a few outside Family Tree DNA.
I was able to locate DNA Y results for several family lines including Melvin, Owens (which I already had), and Callahan. There were also groups for the Browning surname and Wray surname.

R1B and L21 Maps

All of the Haplos I located were for the most common Haplogroup R1b. My Callahan distant cousin had some deep clade results, meaning many SNPs were tested to narrow the families place of origin. His terminal SNP was L21. It's difficult to narrow R1b results without extensive SNP testing. If more SNPs are found then the area may be able to be narrowed further. It does look like this SNP L21 is highly concentrated in Ireland, and constitutes about 90% of  the male population in parts of Ireland. Some call it a Celtic clade?
We were lucky on our Forgey side because the I2 M284 L126 Haplo is far less common. I2 is found throughout Europe. The sub clade M284 is most common in the British Isles and probably originated there 3,000 years ago according the Eupedia. The terminal Haplo L126 is centered in Scotland and Ireland, and probably originated in Scotland according to some sources.
Depending on the rarity of a Haplogroup and related SNP's it is possible to narrow down an old world ancestral location.

Forgey Family Ancestral Haplos