I have a vernier peep sight on my model 1890 their was no other no other rear sight never had one in the notch for they other rear sight my front sight has a flip up sight also one white ivory post when flip up it has a black post whit hoop around it.my gunsmith told me that it was probably mounted at the factory because when we took it off to get the pat: date and model # the the space under the sight was factory perfect. I was given the  rifle  to hunt with when i was 12 years old the person that owned it was in his 60 at the time i am 70. their was no name on the sight. i don’t have any pic on this computer if you would pic let me know and i’ll down load and send some.      thank you                                                                                                                                                                                                                        Dan