the pots load the pickups so youre getting a lower reading.
your current pickups really are vintage sounding. the thing is is that most people recommending pickups dont really have any experience with old basses. they can sound kind of thin through modern amps. old amplification and recordings make them sound fatter and less bright.
i saw your post in another thread about antiquity 2's. the published spec isnt 10.56 on those. its 8.97. ive posted about this in the past but every set of antiquity 2's sounds different. they dont put a consistent amount of turns on these. they might read out as low as 8k or as high as 8.9 like the published spec. sometimes the neck will be hotter than the bridge. sometimes the opposite. that makes every set sound different. either radically or subtly. i talked to mj in the custom shop and she said they intentionally do that since old fender pickups vary. its very different from buying a set of sjb1's where you know what youre going to get every time because theyre always very close in dcr. ive personally had great success with antiquities wound to low 8k for the neck and mid 8k for the bridge. ive gone as far as sending sets into the customs shop to have them pull windings.
one of the most important things ive noticed is that all the repros dont really sound like old pickups even if they have the same amount of turns. im speculating its the magnet composition. all the modern pickups are more strident in the mids and the old pickups are sweeter in the highs. i had duncan rewind the neck pickup of my 62 jazz and the frequency response matched the bridge pickup exactly. an antiquity 2 with the same amount of turns and nearly identical dcr had highs that didnt reach as glassy and low highs/high mids that were more aggressive. i also tried a set of nordstrands in my 62 jazz just for kicks and they were similar to the duncans in the highs. the stock set of pickups is fatter in the low mids and reaches higher in the highs.
if i wanted a legit, true vintage sound for a bass like a custom shop or 62 reissue, id hunt ebay for a late 70's early 80's pair of jazz bass pickups. they usually go for around the same price as a boutique replacement set. if you want more punch, grind etc, any of the replacements are good pickups if not similarish. the fender made pickups are the most different in that they stay true to history in their amount of turns and output. ive owned a set of every thing out there other than the aguilars. still have to try those one day