I haven't received a response yet from Daniel Brustlein's estate to my question about Alain's possible work on the Willie the Whaler ads. The next best thing - I bought a copy of the collection of Alain's New Yorker cartoons "Alain's Steeplechase." Hopefully some clues will be found there.
The book is out of print, but I found one used, but in good condition on Amazon for a mere $3 - it costs more to ship it. Mind you, this is a hard cover book too.
I like many of his paintings too. The painting on the left is quite nice:
Daniel Brustlein, Portrait of Priscilla Morgan, oil on canvas, 1983
Here is the cover of the Steeplechase - soon it shall be mine: