Potential screwless candidate: [Link: alphacommunications.com]

I don't know how the color and finishes might match. One would mount this plate, the keypad, then overlay a screwless Decora ring. The big advantage would be that everything is off the shelf.  The disadvantage is that it might have an overall "patch job" look.

It depends on the surrounding. I once wanted to use a blank plate in hte livingroom in order to pull around a fire break. He called his wife and the three of us went round and round until I asked them to tell me where there was an existing blank plate. After 15 minutes they returned, failing to find the blank. (It was in plain sight in a kitchen soffit. I had cataloged it within seconds of entering the unit.) Then I pointed out that my blank would be buried behind the drapes. One would probably not bury a keypad behind the drapes, but some people don't want to be able to see any technology. I have one customer who didn't want to see any light switches from the livingroom -- they are all down the hall. To me this seems very inconvenient, but I don't live there.