I, too, wish that this were available on DVD. Maybe it will be put onto some budget sci-fi collection DVD, someday--why not? I'm not certain that I still have this on VHS--it's been awhile for viewing, unfortunately.
This film shares a similar problem with the lesser-regarded special effects of the theatrical film "Clash of the Titans"--a work from the same era--that version of the film starred Harry Hamlin, Laurence Olivier, and other legendary Brit actors. Many people wish that some of today's digital wizardry then proved available for such lesser-supported works. Some of that magic might have made this a great TV movie, after all. (Sometimes, though, improbable modern special effects may prove tedious.)
I like Rod Taylor and his movie, too. Really, though, the late '70s is an era in which time travel would have proved more likely to succeed. Thus, the "time-ship," lab, and other prop features appear to be much more "accurate" and likely to succeed at such a task. They're pretty cool! Really, I don't see a problem with John Beck as "scientist," either. He portrays a fellow who proves to be quite calm, logical, and collected.
(Linking John to porn proves very insulting. He proved very highly valued in the '70s and '80s. John was one of the few guys in this biz whom, women--after an initial "shock and awe"--never forget! Really, he's etched forever, easily, as one of the most handsome guys ever to grace a screen. Apparently, that's something which John's harsh critics--mostly men--never will understand.)