I think it's bad advice to recommend Jay contact the people whose products and services are for sale. He wants unbiased opinions.
Personally, I like my '76 Khorns the way they are. I fell in love with the Klipsch sound and other than upgraded crossovers, I intend to keep my Khorns sounding like Khorns. Not everyone agrees with me on this but for those who have upgraded (or swapped) components, you are the folks Jay is looking to for suggestions.
Good luck my friend. I hope you find what you're looking for. Try to hear a pair before you buy if you can. It's a lot of money to make some of these changes and whether or not it is actually an improvement seems to vary from person to person.
Gary you are correct as to what I am looking for in an opinion, I also like the way my speakers sound but. I am thinking they may need a freshing up after all they are over 30 years old. Maybe just new diaphrams or something like that. I would like to keep them original Klipsch, I also want to seal the backs just have not decided which way to do it. I would like to be able to toe them in-out a little to possibly create a better sound if that is possible.
Jay