I am in posession of a boat motor that has been my family for many years.  It is an Oliver Challenger boat motor.  My dad had always said it was a 1942 model, 5 horse, produced during the war years.  I do know it is one heavy piece of machenry (nearly pulling me into a lake at a young age).  It is not functional at this time and has not been used for many years but still has the original fuel tank.  Is there any way I can determine the exact year of manufacture and more about it's history?  Thanks in advance.