Hi, i was just searching for rarest lenses, and i found that. its interesting to see. check the link. and if anyone have some info then share here.. it looks like a beast, and great lens for collectors,
https://www.ebay.co.uk/itm/RAREST-PROTOTYPE-LENS-ON-EARTH-1959-CANON-45-200-mm-F2-8-C35-LENS-HOLY-GRAIL-/163039120661