Originally Posted by
zukahn1
+1 Most of the parts on this style Simplex DR are interchangble if you take them the whole way apart the cage assemble screws off and you can change the cages around.
Taking them apart also affords the opportunity to clean and grease springs #4 & #11, which will help keep the derailleur action springy.
Note that those springs are handed - they have to go back into their respective barrels in the derailleur body.