I'm gonna agree with Bruce's comments above. And I have no idea how it's "supposed" to look. The only time I saw it on the big screen was at an early 70s kiddee matinee, so who knows how good the print really was. I had the vhs but never the DVD. The blu is a revelation.
Seriously, if they were to offer a remake, they might include the 1978 version. It wasn't very good, but it's got Priscilla Barnes as Weena, so all is not lost.