I get what they were going for with the Discoprise, but even then the neck seems too slanted compared to the refit, and the pylons don't seem slanted enough.
I like your suggestion about materials from the old ship being recycled for the new one, but it still takes some mental kung-fu to say the new ship is the same ship its made from.
Interestingly, I don't know if there are any shots of the Refit Enterprise's dedication plaque. I don't know if it even had one.
There is one in Lora Johnson's Mr. Scott's Guide to the Enterprise but I've no idea if it was 100% her invention or based on some unused art.No such thing appears in any of the movies until TNG came around and they reintroduced them.
And there was definitely one in STVI for the Ent-A.