I did a little brainstorming on this show and came up with an idea. It's easy to say that Shinkenger is a major success among critics and fans; as a matter of fact, in a recent TV Asahi Super Sentai 35th Anniversary special, it was ranked #1 among all Super Sentai titles in the Heisei era.
But what if Samurai Sentai Shinkenger was made during the Showa era? Given the limitations of special effects back then, would it have been possible? And would it have been as popular as it is today?
If Shinkenger were made back in the 80s...it would have fewer mecha toys, cheaper effects, and no female ShinkenRed. Otherwise, it would have largely been the same show.
Depending on just when in the era we're talking about, I think you could still have Genta show up as Takeru's childhood friend who's created some new Origami mechs on his own. He just wouldn't be a Shinkenger at the same time.
And Shinkenoh probably would've been made up of at a maximum of three pieces instead of five. And might've shot out from some sort of base robo.