What is a Fireplace Oyster?

Sorry - can't seem to get enough of this January 1951 issue of Gourmet.  There's a delight - and a riddle - on every page.

Consider, for example, this ad for "fireplace oysters" from the "oldest oyster cultivators in U.S.A."  I hoped that the J & JW Elsworth Company was still cultivating their oysters, but the only oystermen I could find in Greenport Long Island were Little Creek Oyster and Widow's Hole.  Neither, sadly, offer "fireplace oysters." I did discover that Fireplace Oysters were served at the Plaza Hotel in 1951 - presumably from the Elsworths.  But I could not find a single other reference to this particular creature.  If anybody has any information on them, I'm curious. 

Then there was this interesting ad for a "yogurt incubator"; who knew Americans were making their own yogurt in 1951?

And finally, a recipe I find hilarious for so many reasons.  Dating from a time when skinless, boneless chicken parts were not a supermarket staple, a time when white bread stood in for rice, it's hard to imagine that this simple dish was actually served in a restaurant. Should you be wondering about that "Key Sauce," it's nothing other than a Pakistani brand of soy sauce.  (My guess is that it's made mostly from water, sugar and caramel coloring, but I couldn't find a picture of the back of the bottle.)

And then, just for fun, an interesting remedy for ailing cats.