Rusted fresh air vent mount on 66 Cuda

Hello, I've started to strip the wiring out of the car and looking at other issues while I'm at it and found the rusted mount flange with holes for the driver side fresh air vent.
Does the POR15 work good to coat it and once dry, apply a fibreglass wrap around the area what I can reach? I know it's temporary for the most part, but it's not out in the elements anymore.

Thanks,
Eric