On a NS SF II Guild (on their website) says the same thing about both the neck and bridge pickups "Alnico 2 magnet, 6.40K resistance".
They sell different surrounds for neck and bridge. They list both a neck and bridge PU for sale but those include the surrounds.
If there were a difference besides the surrounds that could be measured or could influence sound you'd hope Guild would mention it. They don't but we won't prove anything from what they don't say.
From a logistics standpoint it is cheaper/more efficient to make one pickup that could be used in either position and the choice doesn't get made until it is matched with a bezel.
Dealing with vintage Bisonics - 1970 and earlier - I can recall no one claiming they were different. What did make a difference was where the pole pieces were. If the first letter is the PU location and the second is which end the pole pieces were closest to there are the pairs (NN, BN). (NN, BB), (NB, BN) and (NB, BB) and some sound better than others when both PUs are selected.
I could be easily proven wrong if the spacing between pole pieces is different.