Make one?
You can make one if you're half way handy. Just make a plug mold large enough to cover the opening. carefully measure or have someone on the forum measure theirs for you.Use bondo or body putty to make a negative mold from your plug and then use fiberglass cloth and fiberglass GPR or hardening resin from an auto store. When use pam spray or clear plastic as a mold release. When the thing hardens use your skill saw to clean up the edges then sand and paint to match your boat. I've done this many times for seats, hatch covers etc. If I've confused you let me know, it's really not that hard at all and probably cheaper than buying one.steve p.