A very big maybe. Shimano introduced their own design of braze-on sometime in the early or mid 70's (don't quote me on it). It was featured on most of their clamp on shifters and is commonly known as "type A". This is what the curved metal adaptor is adapting to. If you figure out some way to shrink the adaptor down, you can fit the index shifters onto clamp-on shifter bosses. Otherwise, they work on all braze-on shifter bosses.