Shimano- Built in proprietary factories and production lines wholly owned by Shimano one facility in Malaysia and one in Japan
Pinnacle- Owned by Silstar, built by Dawon, Doyo, Kaito, or one of a couple other Chinese Manufacturers
Abu Garcia- Pure Fishing can be built by Dawon, Doyo, or Kaito on the upper end reels. Lower and mid range reels are generally of "farmed" Chinese origin; IE: They can be built at any one of the Chinese factories in lots, there is no guarantee which factory they are coming from, generally.
Lews- Generally built by Doyo and Dawon, with lower end reels being made at either Korean, Sri Lankan, or Chinese facilities.
Pflueger Pure Fishing can be built by Dawon, Doyo, or Kaito on the upper end reels. Lower and mid range reels are generally of "farmed" Chinese origin; IE: They can be built at any one of the Chinese factories in lots, there is no guarantee which factory they are coming from, generally.
BPS- BPS Reels are built much the same as Pure Fishing, and Lews- The caveat being that they are the owners of the tooling. In other cases, the bid goes to the mfr to include tooling.
Cabela's- Can be made in any number of facilities, from Daiwa's own to Dawon and Doyo. As well, they can be of Chinese origin.
Quantum- Mostly made in Chinese facility that shares manufacture of Zebco reels as well. Some are made in a Korean facility, it is unclear of whose facility it actually is. Some say that it is wholly owned by quantum, while Zebco/Quantum deny that is the case.
Diawa Have facilities for OEM mfr in both Japan and Korea. A small Malay facility as well.
Penn- See Pure Fishing- Some Penn Reels are still made in the USA, some are made in China and Korea
Zebco- see Quantum
Rods- generally are made in any number of facilities in China or Korea. With few exceptions on the higher end rods.
How do you know the parts aren't the same? 99.8% of the Chinese reels will be similar, however, the parts will be stamped rather than machined, lower quality metals are used, and lower quality components. Quantum is notorious for this, as is Pure Fishing.