For hobbyists in the US, Sparkfun or Adafruit are a good start. Otherwise go to the big suppliers: Digikey, Farnell and Mouser. China (Aliexpress) supplies pret

For hobbyists in the US, Sparkfun or Adafruit are a good start. Otherwise go to the big suppliers: Digikey, Farnell and Mouser. China (Aliexpress) supplies pretty much everything else. Many dropship on eBay and Amazon too, if you want convenience. You shouldn't need to salvage unless you really want some vintage pot knob or slider that you can't find elsewhere. Industrial hardware usually needs to be tactile (eg operated with gloves). Some modern stuff is better anyway, like mono OLED displays which are far more readable than LCDs.