I sympathize with you all, it can be frustrating to say the least.
I can only get somewhat close to your situation.
Back in '00 I built a 1940 Willys Coupe gasser. It was a fiberglass body, as I could not afford to start out with a steel body. Steel "starter" Willys coupe bodies were hovering in the $30k+ range, if you could find one.
I bought an Outlaw Performance body package, but it was far from a "KIT". But I will admit it was not a true Willys...

When I would go to shows or stop for gas, the same thing happened, what is it and how old etc. I won't go on, you guys know the routine already.
But at one show after being asked many times, one guy with his family came by and asked if it was a KIT car.
I said, "Yes, this kit was the special snap together, no glue required kit. I snapped it together last night just for this show".
He was not impressed with my answer. Sometimes you just have to lead them on and on and on...