[From Reddit: Closeup of Luke Skywalker hanging in the Wampa's cave & his lightsaber stuck in the snow. An extreme zoom shows text embossed. An inset shows it (The Youngling Slayer 9000) was originally part of the flash stem for a vintage camera.]
In Star Wars: Episode V - The Empire
Strikes Back (1980), you can briefly see
that Luke's lightsaber was made in
Rochester, New York.