I'd suggest a visit to a war veterans organization. That will narrow down your search and you can actually speak to some pilots who made the contrails.
But will you have the guts to do this? I'll be waiting, and I've got a good memory.
Will I have the "guts" to do this?
Why would that take "guts"?
Time, access, and interest might be a motivation, if I had an opinion one way or the other.
If I absolutely believe something is true, and it matters, I will work to debunk my own beliefs or support them, whatever springs forth from research.
I worked tirelessly to investigate my religious beliefs and teachings -- until I was satisfied with enough answers that proved that my religion was nothing but lies (based on perhaps a tiny smidgen of truth, way back in history).
I wasn't happy about the results (in fact, I was beyond pissed) but it was important to me not to lie to myself or to be fooled by others.
I don't have an opinion about jet trails or chem trails.
I do have a curiosity about them being so much more prevalent in recent decades than they seemed to be in the past.
I sometimes wonder if it isn't just that the chemistry of the atmosphere has changed.