As far as I know both VBs use 42 and HFSes use 43 gauge, but there might be differences in the alloy of the metal or the type of insulation around the wire. As far as the actual magnets, I would bet they wouldn't be all that different assuming the SEs are in fact using A2 and ceramic.
What exactly are you trying to achieve? I put an A5 in a HFS once, and that tamed it quite a bit vs ceramic, but swapping in a different ceramic probably wouldn't do much. Your USA Vintage Bass is running Alnico 2. You could brighten it up with A4 or A5 but it will be relatively strong for a neck pickup at 8.5K.