More 20 codes and some thin paper

 Here we have a few more 20 year codes and a couple of variations for the 1st Class red shade and its thinning backing paper.

M20L MTIL Much thinner backing paper

M20L MCIL Deeper red Queen's head from Sherlock book, also thin backing paper with very bright fluorescence

2p Dark Green with M20L MAIL

20p Bright green with M20L MAIL

M20L MBIL very bright fluor with a yellow tint