[Zeke3]

Ford approved heater and defroster data is published in a Service Letter dated 12-16-37 for 1937 and 1938 vehicles in the Early Ford V8 Club 1937 book, pages A-37 and A-38.

There is a note when installing a defroster in the open cars and station wagons as follows:
"When installing open car defroster it is necessary to replace the present left hand windshield side finish strip with new strip - 78-711291-B for 1937 open cars, and 81A-741227-B for 1938 open cars."

It looks like the defroster kit for 1938 open cars and station wagons is 81A-18470-B.

I am curious whether the open cars and station wagons only had a defroster vent of the left side since the service letter only mentions replacing the left finish strip.

Hope this information helps your search.