Disco 1 Difflock lever gaitor

Hi every one, got a new disco. 1999 300tdi.
Difflock never worked when I bought it. All apart and now fixed. My question. Part number FRC6872.
Should I have put it on before I reassembled the hi lo lever, I can bolt it down but the small hole for the stick is not big enough to go over the vibration thing. Or does it just sit above it and then the gaiter that rivits down just goes over that.......

Hi, just to see what your talking about, as I’ve never been there, I Googled the number and found this drawing, so if the part is whats arrowed then job done