Though I don't have a Duncan 59 in any of my guitars right now, I really like this model and have one laying around in the parts drawer. I think its the same low-wind, matched coils as a Duncan Seth Lover with a long, rough cast Alnico 5 magnet. Reminds me of the T-Top in my SG. Just not as, I dunno.... good? Its good though. Just not as smooth... it nails the clarity and bass character. I think I just like shorter Alnico 5 magnets.
Interestingly, I believe a lot of real '59 PAFs had Alnico IV bars rather than V. I am sure V was used during the 60s transition to patent sticker pickups, but I know of a lot of examples, particularly from thinline and archtops (and pretty much ALL of the gold covered examples) that had Alnico IV bars. I guess Seymour was less concerned with doing a proper '59 than representing all the transitional PAF/patent sticker, non-t-top buckers we know and love from early SGs and the better small block inlay 335s.
Seriously amazing rhythm pickup. I have it in neck position of my SG and it works great matched with a JB in the bridge. Its so nice and warm and clarity is amazing. I guess this would be really recommended to lots of Les Paul/ SG players.