Scupper drain wood boxes

[Garrison]

Here is a close up of my scupper thru hulls from inside the port hatch by motor well. Does anyones look like this? It seems awfully narrow to have blocks in there. I plan to pull out thru hull and see what is inside and check condition. I was going to fill with epxoy, retap and drill new hole for tube. But seems wise, if there is no solid wood around hte tube to clear this and glass in place wood blocks then drill thru hull into wood. I would appreciate any tips or thoughts for this job.

GR