The wavy thing is a ring expander: it increases the contact pressure between the lower ring and the cylinder bore, to scrape oil off the bore. This makes the lower ring function partly as an oil ring. With an expander under it I doubt you can compress the ring with your fingers - you are likely to need to make a sheet metal ring compressor.
Check whether the rings are exactly the same width. Then see if they are exactly the same depth (one needs to have room under it for the expander). If they are the same dimensions, you'll need to find out which is which from instructions or from someone who knows.
