Your breakfast, madam

You've seen it time and again in old movies.  The lady or gentleman of the 
house is seated at the dining room table or perhaps in bed, propped up by 
pillows, with a tray across the lap.  The butler sets down a plate which
is 
covered by a silver dome with a knob on top.  The purpose of the dome is 
quite evidently to keep the food warm on the trip from the kitchen.

For some reason I have a hankering for one of these.  I'd love sterling,
but 
since I don't want to cash in my retirement account, I fear it will have
to 
be silverplate.  But in order to buy one I have to know what it's called.

I thought there would be tons of them on Ebay, but my search for 
"(silver,silverplate,silverplated,sterling) (dome,domed)" yielded domes
for 
platters or small ones, but not plate-sized ones.

Anny