Ockham Hold
You are absolutely correct ! The COMET was years ahead of the B707.
The 22 days 'gaff' I made was a "cut and paste" omission of mine.
The COMET 4 made aviation history by flying the Atlantic for the first time on 4 Oct 58 (Comet first passenger service 2 May 52) followed by PanAm's Atlantic crosing using the B707-120 those 22 days later; 26 Oct 58. As you say, years and years behind.
Cheers,
TG