Mustang Bass - Bridge Mute Adjustment

[the fuhz]

hello all,

I just got a 1972 Mustang bass and I am trying to figure out how to attach (and properly adjust) the bridge mute gadget.
First off, it is missing the four mounting screws, does anyone know what type they are? I believe that they are not the regular pickguard or bridge screws, but something different.
Ok, so when it comes to the mute bracket, is it supposed to be partially sandwiched underneath the bridge plate and body? Or does the entire thing sit on top of the bridge plate?
Also wanted to know how it is adjusted (pressure against the strings), is it a matter of simply bending the tabs up or down?
Lastly, if I plan on using the mute all the time, should I 'pull back' the string saddles so that the mute pads are in the correct position (ie distance from the nut)? I ask, because right now I have a felt block underneath my strings acting as a temporary mute. When I tune the bass with the block in place, it sounds ok on the low frets, but it is slightly sharp by the time I get up the neck. Im guessing that if I were to move the mute pad back (where the saddles currently are) this issue should be resolved, no? Does that make sense?
Now, I would normally start adjusting things and experiment with what worked, but I dont want to screw anything up.

If anyone can answer these questions, please help, it is appreciated, thanks!

-tf