They will probably sound magnificent already. But if there i a place where to improve, the crossover is the place to look.
Did you ever came across Jeffs Place? It's a blog of a dude messing around with Westminsters. It became a bit of a product placement platform... And it came to a point where everything he changes becomes an epiphany, Makes me skeptical. But still a great read for you to think about the possibilities for changing/improving your speakers. And I honestly believe you don't have to go that far (as in sinking that much $$$) to really improve the sound, work on critical positions and move on from there.
I think the description of the capacitor test (from the caps I've heard) from humblehomemadehifi pretty darn accurate. Anyways, this is a really fun part of working on a speaker. You can change everything back to how it was if you don't like it, etc. etc. Just be sure that when you change something, don't listen to one speaker. You don't replace 2 wheels of a car to check if the tires improve driving comfort..