As the owner of coupe #3 and still waiting for my car to get fixed after about to 2 months after the engine fire incident on the way to Moro Bay, keeping his time table is not John's strong suit (to say it mildly) and giving John a deadline only will cause high blood pressure.
However, I do believe he knows how to fix the car. Mine is also part of the development, and he mentioned that to me when he built mine. With every built he learns more and last time I talked to him, he said that he is trying out some kind of fender liner to prevent the water from coming into the cabin. Not having visited him for a while, I have not seen it myself.
I agree with Gordon and some other posts, try to work with John to get the parts at his cost and do the fix locally. Just be aware that as soon as the car is fixed locally, you have to rely more on our EC fellows to give you a hand in need in the future as he will say that whatever goes wrong afterward is done not by him.
Another thing that I find out dealing with John is that what is important to you might not necessarily be the same to him. The bigger the difference of expectation the bigger the problem you will have with him or vice versa.
I really do hope that this can end up well for both Tom & John and that we all can learn from this experience how to fix things that goes wrong with our replicas, especially the coupe.
However, at the end of the day it is your decision Tom, I just want to wish you good luck
Eddy