No one seems to carry a replacement cover in this size. Any suggestions?

How old is the fitting? Most sewer clean outs are 4". Here's your selection. (see image).
Let me know if you find one. Good luck Tom

Hi fraidy

Your best bet will be to go to a local PLUMBING SUPPLY STORE and talk to the guys at the counter... sure they can find one... :)

Mark

Ferguson Enterprises or Hirsh Pipe and Supply. Google them for contact info. Ferguson is all over US while Hirsh will ship it to you same day.

Good lead. I happen to know this supplier since about 2004. Indeed, they have highly competitive prices - at least in So.California. We have an open account with them and restock our copper supplies exclusively through them...

Yep Milo,

GPS is close to you and have purcahsed some valves and fitting from them with a reasoable price.

John