You can weld to fill this. Your dealer may have the welding rod material so I'd check with them. If you don't have the welder you might check to see what your dealer would charge to plug them. If your dealer doesn't have the material you can order some online from my dealer Merritt Marine. There may be others that you can order from too that I'm not aware of. Here is a link to the material on Merritt Marine's store site:
https://www.merrittmarine.com/store/...oduct_list&c=8
https://www.merrittmarine.com/store/...duct_list&c=22
BTW the Maintenance and Modifications DVD (due out next week) has a section that covers welding repairs for screw holes, gouges, etc. with great video of the procedure.