Teak sole and gunwale/covering boards new install

Beau, I am linking below a cockpit photo taken from the ad that CJ linked.
If your boat is like that, I can't see any additional GRP covering board around the cockpit borders, on top of the deck mould,
It seems to me that it's all an integral part of the mould, extending forward straight to the walkarounds and all the way to the bow.
And if this is the case, the last thing I would think of doing is cutting any relevant GRP thickness from the cockpit borders, which are concurrent to the overall boat strength.

I'm not saying that the boat would split apart if you do that of course, but that's bound to affect the structural integrity to some extent, anyway.
And that's regardless of the thickness/strength of any teak board which you might put on top afterwards, because no matter how properly installed, they would never become concurrent with the rest of the boat construction, anyway.

That said, looking also at some other external photos of that boat published in that ad, frankly I don't think that an additional teak covering board added on top would be so bad, from an aesthetic viewpoint.
Yes, it would create a small step vs. the walkaround of course, but acceptable, also because I don't think it makes sense to go for a huge thickness: half inch as in dewald boat is already good enough, and I wouldn't go above 3/4 anyway.
Also, if given a choice, I would rather have bare GRP as you already have, because imho that's by far the most practical solution bar none, even if I could have the teak at no additional cost. But you already know that.
Bottom line, if you fancy a more woody look, my suggestion would be to fit only caulked planks above the cockpit sole, and if you really want the full monty, fit the teak above the existing GRP boards without touching them.
https://newimages.**************/resize/1/36/7/7373607_20200221120736294_1_XLARGE.jpg

Below is a photo taken from the ad of the only 1998 Post 50' which I found on YW.
I highlighted in yellow and circled in red what, as I understand, is the GRP covering board that you have also in your boat.
Now, if I got that right, are you positive that the yellow thickness (all around the cockpit of course, not just where I highlighted it) is made of a separate board glued upon the GRP mould?
Based on the photo alone, I would have thought that it is instead embedded in the mould, NOT separate and attached afterwards.
And if it is structurally embedded in the mould, the concerns in my previous post remains 100% valid.
Otoh, if it is indeed just an additional board glued on top of the deck structure, then I agree that you could remove it and replace it with teak.
A job that could only be done over my dead body if she were my boat, but feasible, if you are so inclined.

Sorry Beau if I previously missed that point.

But if that additional thickness is indeed part of the mould, it's a mistake to consider it as the equivalent of teak covering boards.
If anything, you should think of it as the equivalent of a structural board in a wooden boat, i.e. something that is there for integrity first and foremost, and just incidentally it's also elegant to look at.

Anyway, back to the point: I fully agree with CJ that if you want the wooden look also around the cockpit, you have no other choice than putting boards above the existing grp.

I can't suggest strongly enough to avoid reducing the existing grp thickness, and walk away from anyone who might tell you it's ok to do that, just in order to please your desire and get to do the job.