Watt/Puppy improvements

I have had Wilson Audio Watt/Puppy 5.1 speakers since the early 90's. They are not upgradeable to the current version, but I would like to improve the sound (primarily the bass but I'm open to all suggestions) without spending $20 grand to get Version 7.

Obviously I can add a couple of subwoofers (if so, which would you suggest: Vandersteen, Entec, Wilson? crossovers?), but I wonder if there are there are modifications to the basic speakers themselves that I should consider? Arthur Salvatore talks about replacing the drivers but has not yet posted specifics.

Have any of you added subwoofers or changed the drivers of the Watts or the Puppies or changed the speaker posts or the Puppy Tails? What about the grills or spikes? Any alternatives? I've seen posts about sandboxes, etc.

I would appreciate whatever advice the members have to improve these speakers.
My impression of my WATT/Puppy 6s was that they were a little hot in the tweeter and didn't go down to the lowest octave. My room is somewhat on the dead side so I was OK with the tweeters, especially after experimenting with toe-in.

I have two subwoofers to supplement the low end. I'm using Sunfire True Sub Signatures. I like the idea of subs because I have flexibility to locate the subs optimally for room modes, etc, while I can place the tweeters for best imaging. The Sunfires go low enough and can punch out the volume when called upon. They also seem fast enough to keep up with the Puppy's -- I haven't observed integration problems.

So far as tinkering with the 6s themselves, I haven't been unhappy enough nor brave enough to disassemble and experimant with a $20,000 pair of speakers.
before i'd go about modifying them, make sure your ear level is at the appropriate height (b/w the tweeter and midrange). an inch makes a dramatic difference.

if you're so inclined, maybe go inside and change the resistors to Roedersteins. i know a friend who did this with his older rockport speakers and it made a helluva difference.

One thing you might think about are either the Marigo tuning dots and or Harmonix tuning dots. I remember reading an article some time ago about the use of these tuning dots on both the drivers and around the binding posts.

I remember this well, because I was surprised that a Wilson product would respond so well to a anti-vibration "tweak". Hope this helps,
Just read your post, because I was searching for "harmonix".
I have two tuning recommendations:
1. Buy a used WHOW III, if possible with the Krell crossover. Equipped with the right amp this will solve your bass problem as it did in my system.
2. I'm currently using the new Elrod speaker cable as puppy tail. It lets more of the music thru.
In the near future I intend to test Harmonix resonance control, but at this point in time I can't comment on this subject.