I too share this uncommon name. However, my father and I had it passed along as a first name. So, tracing how that came to he and I is a little trickier. I have a theory and maybe some here have some info lurking in your data that fits.
The ancestor from which my name comes from is Sphar Bruner. He was born and lived in the Clark/Powell County, Kentucky area. The Sphar family was also in this area of Kentucky at the same time. They manufactured bricks at some point and I have a brick with the "Sphar" name on it.
My theory: Either my Bruner family married into the Sphar family and passed this name along on the Bruner side or.... they were close family friends and used the name out of respect for the Sphar family.
Any thoughts?
Sphar Thomas Burklow, Jr.