Bow plate
The part you are asking about what I call the bow plate. Seems you have some repairs to do so while you are at it, I highly suggest you stay away from the plastic. I have an HC33, 1973. I cut the bow plate out and replaced it with a 5mm thick piece of stainless steel, unpolished. I used cardboard for a template, dry fitted all the hard ware and made sure I tied it in with the toe rails for strength. I elevated the cut plate using 2X4s and rolled my van tire up on it. The curve turned out perfectly to the curviture of the bow. I then layed a solid bed of marine caulk, added another back plate, bolted everything together, and painted it. Then I drill new holes for the bow roller and cleats. man, that baby is strong and if anything goes wrong with it, you can call sea rescue for sure. It is a bit of work but well worth the effort. You can also mount your bow pulpit to it as well.Good luck,Okiman