Don't forget the "bottom of the line" all-steel ("bomb-proof") Eagle which graced many a department store 10-speed in the early-to-mid 1970s. Weighed a ton but shifted well-enough compared to the low-end Huret Alvit and Delrin-body Simplex derailleurs it was up against. IIRC, only the Suntour GT out-performed it in its price range.