I would think that the frame's screw holes could be filled with an epoxy and sanded smooth. The larger hole in the mast for the radar signal cable may require a "patch" that can be riveted in place. I have a patch / cover over an access port in my mast -- it's an AL plate shaped to the contours of the mast and secured with rivets and sealed with a bedding compound.
Leaving the radar signal cable hanging out of the mast probably won't do any harm, but it won't look that great. You could pull out the radar cable and replace it with a light messenger line which you can secure inside the mast at the cable hole. Tie a few knots in the end of the messenger and secure it in place with a big blob of silicone or epoxy.