I'm not certain, but here's a pic of 2-100s and a 300:
http://www.wooljersey.com/gallery/v/...ers+3.JPG.html
the 100 was gaspipe and yes it did have chrome plated ends, so your powder blue job is probably a 100... the metallic blue one in the back of the pic even has dropouts stamped with "Simplex" but they appear to be from plate and not forged. The 300 was 531, I assume all tubes, and sort of on PX-10 level with Stronglight crank, etc. What distinguishes the 200 I'm less sure, cause I thought it was the chrome, but I'm sure there's some improved tubing, perhaps 3-main-tubes of plain 531 or Vitus.