Thanks, 35WINDOW -- Curious ... the picture is a bit small; I'm not sure what it does or how ...
Hey, Brian -- I mentioned using velcro in my opening post. It could do the job, but a clip-on screw cover would be simpler and more secure; if someone hit or brushed up against a button cover that was held on with velcro, they could easily knock it off.
Thanks S10Fan -- Home Depot, eh? Too cool! I'll check that out today!