I am looking for a copy of the play "The Wonderful Ice Cream Suit". Does anyone know where I can get a copy?

The play was published in paperback by Bantam Books in 1972. The book is called THE WONDERFUL ICE CREAM SUIT. You should be able to find reasonably priced copies by searching on the Advanced Book Exchange:
http://www.abebooks.com

A hardcover edition was published in Great Britain in 1973 by Hart-Davis, but it is more rare and expensive. However, if you are interested in the hardcover, the Advanced Book Exchange is also a good place to look.