#1
I finished desoldering parts from this old Yamaha sound board, and came across some stuff that I had no idea as to what they are or their purpose.

The first is what I think are diodes, but they are made of glass, cause I broke a few trying to get them out of the boards. Anybody else run across glass diodes? Are they supposed to be glass? What can I use them for?

Second thing is in the middle of that white VU meter, it has 3 lugs, and some weird metal contact plates in the middle. What the heck is it? What's it's purpose?

Third thing is on the left on the white VU meter. I've seen these before, but the name escapes me. What's it's purpose?

Fourth thing is that big white chunk of clay or something, feels like clay. I'm thinking it's a high watt resistor of some kind, but I'm not sure. It says 5W 3.3kJ on it.

Fifth thing is that little black box. It has 6 lugs, and says

Omron Japan
G2E-184P-M-US
12VDC

What is it? I only found one in the entire board.

And lastly, what can I use these VU meters for? They have 4 lugs, and they all work.

#2
top left is a transistor.
top middle is a trimpot,
glass thing looks like a diode.
white block is a resistor.. i think
black box is a pcb relay
#3
White block is indeed a resistor.
The glass thing that looks like a diode is a diode. Germanium to be exact. Worth keeping if they work.
#4
top left is a transistor.
top middle is a trimpot,
glass thing looks like a diode.
white block is a resistor.. i think
black box is a pcb relay

This is exactly right.
Transistor - 2SA933
Trimpot or variable resistor
Diode - don't know what kind without seeing any markings. It is glass.
5 watt, 3.3k ohm resistor
12v relay, SPDT