No there is no reference to the origin of Bucknard anywhere--that I could find...
I was looking for a place that was "cosmopolitan" but not too detailed by Canon literature. I chose Thornward for it's location at the crossraods of cultures, and the fact it is/was the capital of a country named after a vacuum cleaner.
The connection between Buckie and Evard is my own concoction. I stems from the LG Bissel site; they have a nice gazeteer that gave me the info about the various town and famed inhabitants. I think is is generally agreed upon that Evard is from Bissel, but I made the connection just to make things intersesting, adventure hooks sort of thing.
Sorry about the Skye ref, I promise all the others are correct...right!