"Is it really likely that she would remember one man from another given her age?"
Don't paint too broad a brush on the age factor. While camping in July we met and became aquainted with a retired Armstrong Cork engineer and his wife. He was exactly 86 years old, wheeled his class A motorhome around like a pro and was sharp as a tack.
He had worked on the insulation for missiles and space rockets. He grasp of current and past events was fantastic. (the give away was his colorful description of what should be done to Kerry, the presumed dem boy to be at the time)
Yes, I agree on the age thing, though I think it's the exception not the rule to meet someone as you describe.
Use him for an ablation test. Send him up in an experimental re-entry vehicle? Inquiring Minds Want to Know! :)