Forgot to mention I also have sn 2771 with 'see saw' style rearsight - with flip up/down aperture (pic link below); plus sn 2519 with 'see saw' rearsight without the aperture. The latter was purchased as parts only and recently had new internals made by master craftsman Jeff J. It shoots 695 consistently +/- 5fps with Superdomes.

https://www.flickr.com/photos/tjm_45...15761902401457

Regards
Trevor