Greetings MarchMom from a soon-to-be MayMom.
Are you familiar with the infant/children's boutique Bellini (see http://www.bellini.com/ )? I believe they carry some over-the-counter slip covers for Dutailier Rocker-Gliders, and will custom make slip covers for you too (at a premium). You will need to know the exact model number of your Dutailier Rocker/Glider. A word of caution about Bellini though... Their products aren't exactly in the "bargain" category. But the cost of the slip covers is probably still cheaper than buying a brand new Dutailier.