That isn’t a broad statement Stuart, you’re now into details.

In his congratulatory letter to Heinkel, RJ Mitchell only mentions the HE-70, there is no mention in his letter of ‘rib profiles’ or the NACA 2200 series, it’s doubtful he had time to evaluate them and I’m sure he had his own idea as to which airfoil section to use and plenty of time to apply it.
After all, he was an experienced aircraft designer.

Hopefully, Mr Creosote won’t get annoyed that his thread has gone so far off topic.:(

The letter sent to Ernst Heinkel from RJ Mitchell, wouldn’t have mentioned rib profiles, it was a simple letter of congratulations on, what RJ perceived as a great design; the information would have come from Siegfried Gunter, who was dispatched to the US, by Heinkel specifically, to “bone up” on US A/C designs.

Mitchell was very interested in using elektron for the skinning, of his A/C, this was I believe as a result of his visit to Germany; subsequently it was decided that the manufacture of suitable material in this country was not possible, whether it was financial or otherwise I can’t remember.

In my opinion the Spitfire was unlike any previous design, because; A, it wasn’t a flying boat, B, it wasn’t a racing seaplane, and C, it wasn’t designed to an outdated Airministry specification.

It would appear (from further investigation), that Siegried Gunter and his brother designed the HE70 betweem them, ( Siegfried must have been well thought of as a designer, as post war, the Ruskies kidnapped him, to work on their emerging Mig’s!)