Some years ago I posted about cocking piece peep sights, especially about my solution to the unavailability problem: My conversions of Parker – Hale smallbore target sights
http://forums.nitroexpress.com/showflat.php?Cat=0&Number=151111&an=0&page=2#Post151111
Here is one of my Ersatz P-H “Sportarget No.1” sights on my G.Gibbs Mannlicher-Schoenauer M1900 rifle.