When repairing and editing rolls many, many years ago I came up with a
very unconventional method to make chain perforations.  I am sure that
it will sound very corny, but it worked for me.

Remove the needle from an ordinary old sewing machine, and make a punch
to fit in the needle shaft chuck.  Drill the plate where the needle
goes down through, to fit the punch.

Experiment first on a piece of paper until you get the feel of it and
get good at it.  Draw a very straight line on the roll where you want
the chain perforation.  Adjust the presser foot tension so that the
paper will go through but not damage the paper.  Also adjust the stich
length to the desired distance between the chain perforations.

Go very slowly, and this device will perforate nice chains in the
repair work.

Bruce Clark, Interlaken New York

 [ A picturesque slang German term for the chained pattern of holes
 [ is "der Rosenkranz" : "the rosary" !   -- Robbie