Does a good Spaghetti Western fall into the Steampunk category ?
Terence Hill & Bud Spencer made some excellent movies in the 60s and early 70s such as the trinity series. The "dollars" series with Clint Eastwood were good
There were some great black n white horror movies from the 30s- 50s set in the humid jungles, outer space and under water. White Zombie series, Island of Lost souls, The invisible Ray. Dr Phibes series, Creature from the Black lagoon. Monster from the Ocean floor, Flash Gordon, Barbarella
and many many more.
Nothing beats a rudimentary mechanical giant deep sea or space monster.