Spring Cleaning

I was doing some deep cleaning in the kitchen one day.  I wiped down all of the cabinets inside and out, and then decided to tackle all of the dust that builds up on the tops of the cupboards.  I got up on the counters to start cleaning, and, this is what I found:

See the smaller ledge just above the brass and silver bowls?  That is where I found it.  I'm guessing that the artist's name was Isaac, although he failed to sign his work.