TIG Filler rod questions (various bizarre stuff)

Got a bucket of welding rods yesterday. Some questions.

1. I have some yellow rods that look like brass rod or bronze. Any idea what they may be.

1. I have some 410 stainless filler rods. Can they be used with other grades of stainless (308, 312 etc).

2. I have some strange rods for welding tool steel. Some say air quenching. What are they for, welding or buildup or both?

1. I have a box of long (2 feet long) dull grey tungsten rods, maybe

Also got some that looks like regular steel rods covered with very large amount of flux. I think that I will just throw those away, but I have a suspicion that these may be for cast iron.

thanks