Removable forestay
Our NIC31 has a removable inner forestay fitted. The deck attachment is connected by a steel rod to a large fitting which is laminated to the hull in the anchor well. Does anybody know what this fitting is originally supposed to be used for? Did other owners notice a similar arrangement for the forestay? (We noticed Tramontana's setup).
The attachments that you describe were likely added by a previous owner to reinforce the boat for the added stress to the hull/deck/rig caused by having an inner forestay, either fixed or removable. The Nic 31 was designed as a sloop rig with a single forestay. The standard, factory spec boat doesn't have these fittings.
Re: Removable forestay
When we bought her, I found that the attachment at the bottom of the anchor chain well seemed to be originally laminated into the hull (no visible work after the original lamination). Both the end of the anchor chain and the end of the removable forestay were attached to it. I first supposed that the purpose of this attachment (it is like a semi-circular steel rod, about 3/4" dia, completely embedded in the hull. I will take a picture of it next time.