Photos and a brand name?
Thinking outside the box a bit. Check your local craft store for needlepoint frames. Usually you can find something fairly close to the correct diameter. Buy 2 and nest them with some nylon bug screen in between.
Lena made these using plastic window screen, binding and Velcro. Every year or so we have to renew the Velcro on the window frames but the screens sure store easily when we’re not using them.