a) Should be the same.
b) Probably - and this was my first thought.
c) Maybe - who knows? Way too many variables to compare subtleties in a finish from pic to pic, IMO.
d) YES. Remember - especially with transparent finishes - each piece of wood is unique - and there will always be grain and color variations from piece to piece, such is the nature, well, nature.

And yeah - Spud's BCB is one of the prettiest guitars I've ever seen.