Takao Saito, best known as creator of Golgo 13, was also responsible for two ninja manga: Kage Gari in the 70’s (the Shadow Hunters, which also spawned two films), and Zanpei Kumotoriin the 80’s. The latter featured a Connery-esque shinobi getting into all sorts of mischief.
Here’s a few choice pages:
Zanpei Kumotori wasn’t exactly revolutionary or even a genre milestone, but it had a lot of that Golgo tone and enough meat-and-potatoes ninja action to be a hit for years.
I’ve found several volumes of reprints on YesAsia.com.