I have a 1901 Rifle with 1901 rear sight.  I read that you release the sight base to adjust windage by flipping that flipper, moving the base, then flip it back?  My flipper don't flip.  Stuck?

I removed the sight, tapped the side a bit and got the 0 lines lined up.  Then remounted the sight.

My question is, do these thing tend to get sticky, rust or am I not doing things correctly?  Should I soak it in something for while?  :-?