I've seen loading tips like "assault rifles with a Vladof barrel fire faster as you keep the trigger held"; this clearly refer to the "Spinigun" triple gatling barrel assault rifles. Aside from that and the Elemental accessory (which I believe is exclusively made by Maliwan) I don't really know how to recognize which parts come from other manufacturers. Note that these parts show up on other manufacturer's guns, I've seen Bandit and Jakob's Spiniguns and elemental guns from everyone but Jakob's.
Are there other parts that are made by specific manufacturers that show up on guns? Most parts appear to be exclusive to a manufacturer's guns (e.g. Tediore's clean, mass-produced aesthetic), but it's implied certain parts can be on other manufacturer's guns, like the Vladof rifle barrel. How can I recognize them?