Kathy, it is normal for C skinneri to get dry sheaths, since this is a Spring bloomer. I would watch out not to give it additional light at "unnatural" hours to keep the timing on track.
Remember that I had to really cut the solid main clump straight through, so if you lose a pbulb at the edge of the division, that might be due to that? Adding medium? I would think that depends on the amount of watering you do. Do you see nice new roots?
I don't think L lundii blooms last that long. I forgot exactly how long, but it was in the range of days, not weeks.
