You can get Black Ring by earning points in Triad -Maximum Attack- 1, 2, or 3.
Both Double Cannon and Guld Milla require Joint Parts, but since V2 doesn't have item combinations, you need another way to put them together...
You can technically find Lavis Blade and Handgun: Guld/Milla without the EP; you just never will, thanks to Sega's absurd rates. You can't find Joint Parts at all without the EP, though.