Hull vents 1978 23 SF

[EagleOCNJ]

I know the topic has been covered but it seems that some of these boats have diff. size vents. Mine are 16 -17 " long and are in need of replacement. Id love to find some stainless louvered vents that DO NOT need to enter the opening but be mounted externally.

Any suggestions? Ive looked through commercially distributed catalogs from Attwood, Taco, Buck Algonquin, Perko, and others and no luck. None of the available are as long as mine except the plastic jobs that have to be cut (for the back two) to fit.