The Ferret Store has ramps for the Midwest cage.  I just purchased 3 of
the short variety.  They do have the longer version also.
 
www.Ferretstore.com
Small or short: MW140RMPS $14.41 ea
Large or Long: MW140 RMPL $16.02 ea
 
Check out their website.
 
Win  (Charlie, Tafi and Cyndi Lou the ferts)
[Posted in FML issue 5150]