G'day Maggie, I couldn't find much either, what I did find and I do not know if these are the instructions you are using, but what I infer from them is that a chain was used on one side and a rope on the other, see pics below,
This seems to imply that there was only one chain box on the port side.
and on this pic it states, Chain Whelp ( iron ) on the port side, and on the starboard side, Whelp ( wood ), which would be for Rope, hope this helps you .
I have attached a couple of pics of a small fishing boat that I built, and it uses rope for the
Grappling hook, and the rope was just coiled on the deck,
This of course I realize is a much smaller boat.
best regards John.