[PW] Children's book with number names

[Donna Penz]

I saw this query on a book somewhere else and am intrigued enough to ask for help here.  The questioner wrote:
 

		Hi, this is on behalf of a friend, who has been searching for this book for many years.
		
		Here's what she can remember of it:
		
		I took it out of the school library in 1978, but I was changing schools in May and I had to leave without finishing it. In desperation, I read the last few pages so I do know how the book ended, but I would love to read the whole thing. It was a hardcover book with a green jacket with a line drawing of some children on it. I'm not sure where the action was set but I read it in England. The main character was an only child and very lonely - i think his name was Martin. A family with four children came to live nearby; they all had peculiar nicknames to do with numbers: I can't remember what the oldest two were called, but the third was Troy and I think the fourth may have been Quad. I rather think boats were involved in the storyline somehow. At the end Martin was invited to join the family as an honorary member and given the name Quin
		
		Any help would be grand.

 
Thanks in advance!
 
 
Donna L. Penz
Reference Librarian
West Atlantic Avenue Branch Library
Palm Beach County Library System
penzd at pbclibrary.org - (561) 498-3110