Building up cutout transom

[Hoover]

OK guys dont shoot me for stupidity. Love this site and it has really inspired me. I have a 23 ft C Hawk...yea I know I know but there isnt a classic forum for that and after searching many websites have found nothing that compares to you guys. Anyway I want to change the cutout transom to solid with a bracket for a single outboard. Thing is my transom is solid.(No soft spots or rot) Can the transom be filled in from the inside without taking it down to the outer shell. Also I want to put a fishbox in transom but I dont plan on anything nearly as fancy or nice as what strick did because I am new to this. Thanks for at least reading a non seacraft owners participation in this sight. If all goes well with this project and I get the itch like I think I will I just might move up to a SEACRAFT. Thanks