1963 Jaguar mute assembly
This thing goes in there and then something rocks on this and something is underneath, too.
The foam part of the mute, which actually the whole thing is all about (no muting without it), is missing. Mouse-pad foam or black self-adhesive weatherstripping is a common replacement, and there should be the “official” replacement part (from the MIA reissues) available.
Up to now the picture showed the spring assemply orientated in a wrong way. As can be seen on Mel’s tech page, the screw depresses on the metal part and the spring pushes from below, not as it was hitherto shown in my picture with the screw penetrating the spring.
Many thanks to John Holmes and Kirk Kopetsky for the hint.
Over at the offsetguitars.com forum, guitar whisperer Sookwinder has a good description how this all is supposed to work when installed:
1. the slug and the spring sit in the hole in the body. the slug on top.
2. the hole has to be sufficiently wide enough so as you press the slug into the body, nothing gets stuck. In fact if you look at a lot of vintage jag bodies, the slug hole is a pretty roughly drilled hole... just get it wide enough.
3. the mute (including secured thin bolt) in placed on top of the slug and pushed down wards. then two screws are used to screw to mute to the body. these screws are not screwed in all the way, but rather to a point where the mute cab rock backwards and forwards.
4. the rocking of the mute back and forth (once pressure is applied by the player in one or another direction) causes the attached bolt on the mute to go to one side/egde of the slug. The bolt is at a diagonal angle to the top of the slug (effectively shorter) and allows the slug/spring to slightly rise. If the mute is adjusted in the other position, it will go to the other side of teh slug... but has to go through a point where the mute is parallel with the body and so the bolt is facing downwatds, making the slug and spring compress more and so the whole system wants to relieve the force and allows it to easily move to the position where the mutes bolt is at an angle resting on the side of the slug.
Be sure to visit that thread, there are some good pictures in there, as well and info on the differences between vintage and new(er) AVRI parts.