The 5 unit, 11/16" Telex width tape is easy to get, it is the 1" that is the problem.
Provided you don't want a whole 2000' reel then the easiest way is to cut down thermal fax rolls. Can buy cutting discs, about 2" diameter with a razor sharp edge, set up with the correct spacer and a straight edge. If you have access to a lathe then a scalpel in the tool post holder and the fax roll in the chuck and slowly and gently feed the scalpel in.
Why thermal fax paper? Cheap, good quality, easily available but any paper roll will do.