With all that said and agreed, some of the more traditional means of knowing about each others' whereabouts we not utilized either.
The Spitfire didn't have any lights (strobe, ACL) on, despite wearing a camouflage painting (green, grey), blasting at 200 kts.
The Cessna was not on the traffic frequency.
Nevertheless, it seems to me quite an impressive work to analyze these events to such extent.