Cels Forum

There is a method that cel restorers use that can get
around a cel with a crease, although depending on the
value of the cel the repairs might exceed the value
of the cel. 

What is sometimes done when there is a lot of creasing
or holes on a cel is the images on the cel are all cut 
out and then pasted onto a new piece of acetate. This is
a common process that is done on cels made before 1940,
as they were done on nitrate stock; which rots very 
easily if not kept in the right enviroment.  If you go
through with this process and ever sell the cel be sure
to tell the buyer you had the cel restored and provide
the documentation as the cel will no longer have the 
timing marks, something which disturbs some people.

Another alternative is to frame the cel. While it doesn't
get rid of the crease, you don't see it anymore (if it's
near an edge that can be hidden).  

Brian