Now that the dust has settled on the FCC decision to reallocate certain frequencies (I think bands 27-9), what does it mean in terms of working with and selling (used) a Lectrosonics 400/411 system in band 29. Will it still work, and it is legal to use?

First it will continue to work, it won't just suddenly shut off. Second, 700mhz and up is now considered to be off limits for our type of use by the FCC.
I know a couple of folks that are still using the freqs and so far the frequency police haven't come for them but would I want to chance the posible interference? Probably not. If you already have them, maybe they have some sort of trade out program, I think Sennheiser had one for a while.

We do still offer a "re-blocking" service and the cost is that of the required circuit boards and a bit of labor. It is far less than buying new. Please contact our service dept. at 1800-821-1121 and request a quote. Have your products and serial numbers on hand.