As mine was when I got it.  Took her to a local sailboat guy.  He put her in slings and lowered the board, how I don't know, ground it down and painted. It has worked perfect for 5 years.  About 150 bucks.  Good luck.
Dave #49
----- Original Message -----
From: wayne yeargain
To: montgomery_boats@mailman.xmission.com
Sent: Tuesday, July 02, 2002 9:30 PM
Subject: M_Boats: Stuck centerboard

Hate to drag up this old tired dog but my recently purchased ('76 M17) has refused to lower her centerboard.
Intrepid went on her maiden voyage, nothing went twang but centerboard was not forthcoming. Tried tapping on the
case, still nothing.
 
I was told it had been in storage for several years, (could be dirt dobbers or rust.)
 
Still sailed pretty good without the c'board.
 
Any suggestions will be greatly appreciated.
 
Wayne M17 #204 "Intrepid"