Of course, the whole "1701" business could be a case of cryptonesia
. Matt Jefferies suggested it and Gene liked it because it "rang a bell".
Jefferies' Waco plane had a registry starting with "17". There had been some debate whether he got the plane prior or after his work for Star Trek. Back in those days, could you just pick the registry or make a request the authorities would listen to (considering it was the Enterprise's
designer making this request)?
Already the narration at the beginning of "Forbidden Planet" is clear evidence, that Roddenberry borrowed from it, IMHO. But I can't find fault with that.
In the early 1970's, the production design in films like "Silent Running" or "Dark Star" were apparently trying to claim "we are the same league as 2001" (or making fun of it), so I'd say that Roddenberry also wanted to claim or suggest that Star Trek is the same league as "Forbidden Planet".
The only thing I still don't like, is that both pilots ("The Cage" and "Where No Man Has Gone Before") were just too derivative regarding the plot.
In "The Cage" we had an alien civilization that devastated the surface of their planet and had to relocate underground.
Yawn...the Krell in "Forbidden Planet" had accomplished the same plus eliminating themselves (interestingly, the mutants in "Planet of the Apes" look like they are descendants of the Talosians. Wonder how Roddenberry must have felt getting a taste of his own "medicine"
Then we have "Where No Man Has Gone Before" where we have a human being whose only difference to Dr. Mobius in "Forbidden Planet" is that he is consciously aware of his god-like powers (Yawn again).
For me it's still a great thing that with the first regular episode produced ("The Corbomite Maneuver") TOS had found its own and unique style (in comparison it took TNG one or two seasons before they truly accomplished to cut the umbilical cord to TOS).