Two things immediately come to mind First, from the jagged edges of the tape, it must have been in something very much like a normal scotch tape dispenser. The jagged edges look like the teeth from one of those holders. Second, if the tape is fabric, then the most commonly available material like that would be the white medical tape that doctors and/or hospitals used if you had a small wound and covered it up with gauze or a pad of cotton batton. I'm not completely sure this tape is still even made. I get a similar type of tape every time I go for a blood test but it appears to be plastic based and not cloth. I also recall that this tape dispense came in a round pressed tin can with a snap on lid and hole through the center. Bottom line, I think your first place to look for it is a pharmacy.
I have picked up the issue of Mopar Action with your car featured but haven't had the opportunity to read it thoroughly. I'm really hoping the author appreciates what you have achieved with the restoration of your car. "Restoration" has become a badly over-used and incorrectly used term in the last 10-15 years. Rebuilding a car to suit the owner's taste and calling it restored is not a restoration. You have achieved an actual restoration (well, next time you'll be able to stay a little closer to those 45 second cycle times - LOL!) and deserve every accolade you have received. I also will repeat my comment that the judges as experienced as they are do not seem to have real world Chrysler assembly plant experience. If they do not like fluid drips, I can only imagine how they would score orange peel and paint runs - all of which are very much "original".
