Our local Agway store had cage material, clips and latches.  YOu can probably
find the plastic type of slide hook that work quite well.  The clip
essentially looks like a letter "q".  A portion of the straight side of the
"q" is spring loaded and slided back and forth (best way I can describe it
anyhow).  As far as the covers for the door edge goes, if you clip just the
top, end wires of the cage material (very hard to describe) one on each end
of the bottom of the door opening, then fold the section down, the folded
section makes a very smooth surface for the ferret to scoot over
 
    |              Door Opening
 
                           |
    |                                                              |
    |                                                              |
    |X___X|_____|_____|_____|X___X|
    |           |            |            |            |           |
    |_____|____  |_____|_____|_____|  (cut wire at 'X'.  Remove wire.  Fold
down section)
 Never claimed I was an artist, OK  :>)
 
Dick Bossart
[Posted in FML issue 1084]