Tweeter Capacitor Upgrade (Coincident PREs)

"I suspect the Duelund by=pass caps might give the accutrons a bit too much resolution. They are not lacking in air and extension even with the Solens, and he could end up with a hyper detailed presentation would be my concern."
It works opposite.
I put Duelund Cu-Sn bypass (in my Altec 604E Werner Jagusch Crossover) bypassing old vintage oil capacitor.
As result a lot of music that sounded bad before started sound good.
After that I replaced old vintage oil capacitor to Duelund RS capacitor with the same bypass Duelund Cu-Sn capacitor. It gave me big improvement in transparency and musicality.
After that I exchanged Belden internal wire to Duelund 16AVG Cu-Sn wire. I can say this wire is magical.

Let me know if you want to buy Jupiter caps. I have different values than I would like to unload.   

Do you have 8uF?

Thanks again for all the conversation... All very useful.

At this time, I am not really inclined to do anything besides replace the tweeter capacitor, but clearly there's a lot to think about there.  I think improvement there is highly likely, but I'm a little less confident about the wiring/inductor/post changes. My soldering skills are improving, but I prefer not to touch what I don't have to.

And in regards to some of the conversation, I've looked inside the speakers and indeed, the only cap is on the tweeter. The mid-range is connected directly to the binding posts, and I'm pretty confident that the only component inside the subwoofer cabinet is the large inductor coil.