Ive not sailed your boat type; but, many of such boats from this era had their mainsail halyard setup quite different from todays 'typical'. If the halyard is or was wire spliced to a 'rope'; and, the wire had a little ball or several balls swaged directly to the wire portion, and the mast had either something that looked like a 'claw' attached to it or had a funny looking metal 'jam cleat' attached to the mast.
..... here's how to raise and set up the mainsail. Wire halyards are quite passe and have been replaced with small diameter super-strong hi-tech, small diameter polymer lines. If your wire halyard is no more, you'll have to improvise the following:
• Raise the gooseneck on its slide ALL the WAY as far as it can go.
• Raise the mainsail on its wire halyard as far as it will go up the mast.
• Insert the ball on the wire halyard into its 'claw', make a cleat hitch onto the mast mounted cleat near the bottom of the mast with the rope portion of the halyard. The ball on the wire halyard takes ALL the strain of the halyard.
• Open the pin-stop on the gooseneck and bring the gooseneck down until the boom position is 'just' supported by the halyard tension (no tension in the mainsail luff).
••• Then .... (important) Stretch out the luff of the mainsail, by bringing the gooseneck DOWN another 2.0 inches.
Thats the 'basic setting' for the gooseneck height for sailing in 12-15 kts.
You may find a black band or the remnants of a black band around the margin of the mast near or slightly lower than this 'final' position of the gooseneck slide. In HIGH winds the gooseneck is positioned so that the TOP of the boom is equal to the top of the black band.
