Reused sets/props
Mr. Allen must've been an early environmentalist as he sure liked to recycle props, sets, shots, music, sound/visual effects and even actors! LOL
I do give him kudos for having a female security chief (and an Asian one at that!) long before Lt. Yar on Star Trek Next Generation.
In Time Tunnel (and at the 2:05 mark in this pilot) there's a downward looking shot inside the underground complex that features elevator pods moving up and down and walkways running across the open void in the center. These 'walls' in this shot later appear in the control room scene at 5:51 where a meeting is held.
Notice the background props that resemble tall apartment buildings with lots of windows, these are what I'm talking about.
As if all of this wasn't cheesy enough, I can't recall ever seeing the use of matte paintings for interior shots! Check out the establishing shot of a control center at 2:10 (thru to 2:27)
Go to YouTube and see if you agree!
PS What a let down for Zefram Cochrane LOL