This is a identity parade of touring/mountain bike models weighing less than 220g excluding hanger plate. For examples weighed with a hanger plate, I have estimated a hanger plate as weighing 35g. They are shown in order of increasing weight.
Note that the first seven examples weigh less than 190g and would qualify as ultralight racing derailleurs (see page 1). The Huret Jubilee (2248) is the third lightest derailleur in the whole collection - far lighter than any Campagnolo or Zeus racing derailleur.
Huret Jubilee (2248) 1974?
SRAM Plasma (1st style) 1998?