7x35 insta-focus by THUMB on rt eyepiece; catches/sticks; has tiny bolt with extended end rides in slanted groove inside eyepiece; seems to be steel riding against aluminum. is something missing?ie nylon bushing or such? (30ish yrs old, japan made #NX2319 on center)

Optics - Bushnell - "Insta-Focus" Binoculars