Used on Alpine series 3, 4 and VERY late series 5 Alpines too. Most of the series 5 Alpines had self adjusting rear wheel cylinder, until Rootes figured out that they were crap and reverted to the original system. At least will help you expand your search! I finally came up with a set of these, but it took quite a lot of searching.
There are a couple of alternate solutions.. you can substitute the clips used on the self adjusting (series 5 Alpine) wheel cylinder, they will work. alternatively you can remove the extension on the backplate that retains the rear wheel cylinder boot and use the series 1/2 clips and boot which are also the same as TR4-6 and Austin Healey from 56-67