??? Why would you want to do that? LED's run on about 3V DC each, and a Flourescent ballast will try to push something like 500-600V AC... Somethings going to fry...

Well, the old wiring has to be replaced too. Otherwise this would be simple. Most of the house is wired with the old natural-rubber BX, which is now crumbling - I've found bare wire in some junction boxes. The basement is highly accessible, so my plan is to fish Romex up from the basement. This is easy for the outlets. For cove lighting, my plan was to use a hole saw through the plaster (same as for the outlets) then a long flexible drill bit to get through the blocking inside the wall. Then it should be possible to fish power down to the basement as well. Actual middle-of-the-ceiling boxes would be a lot harder to do that way, so there might be some more plaster damage involved with those. It sounds like with the HomeWorks system, I still have to run 14/3 from the luminaire to the switch.. or is there a method that allows only Class 2 to the "switch"? I read the HomeWorks install guide, but don't see a comprehensive system design document on Lutron's site. Am I just missing it, or is there somewhere else I should be looking? I would rather stay away from RF if possible.

Is it really necessary to have separate switching of the two lamps in the cases? If not, then you can just use an ordinary small can type 2-lamp electronic ballast and fit new T8 lamps. That's the easiest answer. If you do need separate switching then you'll just have to find room for two ballasts. Usually if one will fit, two will, if placed end to end. You will probably have to drill and tap new holes for the second ballast. If room is extremely tight in the fixtures, maybe you could remote the ballasts. Another possibility would be to use 3 or 4 PL type CF lamps. The mag ballasts for them are usually very small, about the size of a voice coil transformer from an AC-DC table radio (if you're old enough to remember those). You'd have to change out the lampholders too, of course. I see many hours of labor in your future. ;-) Maybe new T-4 or T-5 undercounter fixtures would fit in the cases.

Securing the nut is just fine. We do it all the time that way when replacing ballasts.