Roof Vents for 79 1600

[blacklab]

I'm replacing the roof vent in the roof center of my 1979 model 1600. The vent I got from my local RV shop slightly smaller than the original, leaving a screw hole on each corner outside the flange.
Is it possible to get one to match the original?
Is the smaller vent in the bathroom available anywhere? I'd like to reseal it as well, but not sure it will survive.

[Gilles]

You can find here:
https://www.rvandvansurplus.com/roof...Vehicletype=RV

Here:
https://www.rvsupplyparts.com/catalo...-c1g-8117.html

In Canada here:
https://www.campkins.com/Parts-Detai...6#.VwP9dqThCUl

[blacklab]

Thank you!!