Wardrobe Refashion: Jersey Knit Colour Block Dress

1 blue jersey dress that I grew less fond of
+ 1 Purple jersey tunic that I'd like to wear more often
= 1 Jersey Knit Color Block Dress.
What I found difficulty was: matching a wider Purple bodice to a narrower Blue skirt bottom. Then, the little voice inside my head said, "How would you sew elastic bands?" 
We stretch!
Fear of Sewing Jersey Knits: 0 - Me: 1
Another plus point was tackling my first "fear" of adjusting the Differential Feed (DF) of the serger. Jersey knits do not like to be treated as a "normal" weaved fabric -- they are class of their own, apparently.
The question to you, my dear friend, is: