Chris brings up a good point/question. I bought an Argentinian '33 Fordor. It had a filled top from the factory. There were no channels in the car for the insert and it had matching welds on every other part of the car. I see your car has left side wiper so it probably wasn't a RHD. But have you seen the underside where the insert might go? I'm asking because I'm interested in your car, and also about other places filling the tops. Maybe Canada was doing this as well?