I have an '05 Parker 2830 with round 3" ID scuppers. My original ones need to be replaced but I can't find a replacement. Parker doesn't even have a replacement. I like the "Attwood Scupper Valve 3876-3" but the OD is 2 3/4" and along everything else I find isn't big enough. Anyone out there have any ideas to help me out to avoid having to break out the fiberglass mods? TIA