Bubble in Transom (I/O conversion)

[TheBizzTwo]

This is my first post, about to go down the path of restoring a 1976 Seacraft 23' and am pretty jazzed about it ... I also realize it's going to be a lot of work!

The owner before me rebuilt the transom using coosa board and had the entire process well documented. The boat was originally an I/O and they used the original transom skin to mount the coosa to (and removed the rest). Long story short, that's as far as into the project as they. Five years later there is a bubble showing (delam?) and I am guessing it is right where the void in the skin was for the original I/O. It's a little hard to make out, but its almost smack dab in the middle of the transom.

The plan is to bracket the boat and add an outboard, but not sure 1) how concerned about this I should be? 2) if there is an solution to fix it? The boat has not seen water since the transom was redone.

Thanks in advance. I plan on reading these forums daily for the foreseeable future.