As already stated, that was a steal! Not only can you find the old stuff still available on eBay and through other channels, but you can also modify the crossover on those speakers using Al Klappenberger's DIY Plans
(see the "Klipsch" section under "Extreme Crossovers"). I've used his crossovers in my LaScala's with mixed results, but when they work, they are a very significant improvement over stock. They did not work for me in a smaller room though, where I preferred the stock AA crossovers. There are some simple things you can do to improve upon the stock Cornwall. First off replace the stock zip-cord wiring harness with some quality wires such as DH Labs silver, or alternatively I've heard some folks have been happy with Paul Speltz Anti-Cables. Also, assuming yours is the older Cornwall with the screw-down back, you may want to consider adding some thin foam weather stripping around the perimeter of the seal. If you really want to go to town replace the stock plywood back with a 1" MDF (you may need longer screws) for a bit of reinforcement in your bass. Internal bracing in those large cabinets would not hurt either and should be fairly simple. The body of your sqwawker horn is likely metal. Attach some dampening sheets to the outside of the horn to eliminate any 'ringing'. You can get that stuff from PartsExpress pretty inexpensively. Cut the sheets to fit and use a hair dryer or heat gun to get it to conform tightly to the horn.
Enjoy! Those speakers will sound great with a moderately powered tube amp. They are extremely efficient.