You should have installed plaster rings while the walls were uncovered. You can easily make your own SO-239 wall connectors with blank plates either plastic or preferably metal. Get some SO-239 feed through barrels and drill holes in the wall plates to fit. You will probably want to use an angle connector on the inside of the wall, especially insulated walls to prevent having to bend the coax at too great an angle.
I have a double gang blank wall plate that I drilled out for 6 evenly spaced barrels. Looks really professional. There is a matching plate installed in the overhang of the roof line so that the connectors are installed vertically. It is far enough back in the overhang so that coax seal or similar products are really not needed unless you are hyper about it. 73, John, W4AWM
