Shiplap over existing shiplap porch?

I'm attempting to ship lap over an existing shiplap porch that was installed 30+ years ago and is cracking and has gaps allover and the wife wants it stained….and I wasn't about to start sanding this all down over my head.

From afar in the pics it looks fine but up close it isn't. I've bought new shiplap boards, and stained them a more oak wood color that the wife wanted. I was planning to just match the length of the boards that are already on the ceiling and cut the new boards to length to match and throw it up over it.

Is this feasible or am I underthinking this? Will I run into issues because the trim is already up? There is a 1×2 board it appears all around the perimeter of the ceiling, and the new boards fit right up against it… I'm thinking my only issue is going to be getting that last board into place because there will hardly be any room. Any advice/thoughts are much appreciated!