If the reflector gunsight screen is fitted and doing nothing useful, perhaps the image could be projected on to it?
Sure, excellent idea, but with which complexity and costs to get that done ? Mixing 1945 and 2020 technologies is not that easy .
If it were me, I would want any help I could get to see hidden aircraft
Sure again , but a far cheaper and simplier anticollsion system that a caera / HUD would be if both aircrfaft had been fitted with a traffic alert , like a FLARM that we all in Europe in the gilder community.for instance Unfortunately not working above 250 Kts.,so not made for high peformance aircraft. ..
But again , in a flying display , especially y during a high speed , low level trajectory , trying to catch another aircraft ( the P-51s) and stay within the display line , you are only looking outside , not to a screen , unless it beeps in the heaset ( which the FLARM does)