[trebleshot]

Upper left blue gun belongs to Transformers G1 Skalor. There is another piece that combines with it to form a double-barreled gun.

Red sword belongs to Transformers G1 Snarl.

Missile Launcher next to the sword goes to Transformers G1 Slag.

Missile next to that launcher belongs to Transformers G1 Optimus Prime.

Missile Launcher on the second row far right goes to Transformers G1 Snarl.

Large black "gun" on the bottom row is the middle section of a gun stand for one of the six Seacons (possibly Skalor, since you have one of his guns too). There is a base piece and a top part where the figure attaches that are missing.

Purple gun on the bottom right belongs to Transformers G1 Blitzwing.