HR7WC 1938 Honduras
This is an undercover QSL. Mr. E.T. "Tom" Clark says on the card; "Send crd in envelope. Leave off my call letters."
In the Feb. 1938 issue of Radio magazine the operator of HRO said he was ex-HR7WC and HR1TC.
QSL from the estate of W3EVW
Info courtesy of W5KNE