Alan,

I am not sure if you are referring to the bottom of the mast or the base on the crossbar here.

(Seems as if there is a hole drilled in the mast rotation limiter in the base in their diagrams.) .

There are a couple of tangs on the base on the crossbar with holes drilled in them. They face toward the stern. Fasten the hinge link there with a pin and split rings. The other pin will have a hole for a split ring that you tie a light line to, so you don't lose it. Pin the mast to the link with that pin, raise the mast and fasten the forestay. Then pull out the pin so the mast can rotate. I usually stick the loose pin under a loop in the tramp lacing so it isn't just hanging on the string.

Howard