What a great card! Superb image of the Swiss protecting their neutrality, pointing to where everything is happening!
The stamp is SG425, the high value of the two stamp set for the National Fete and 650th Anniversary of the Swiss Confederation, issued 1941. Stanley Gibbons gives a CV of 70p used, but the Swiss stamps of the 30's and 40s are excellent to look at, and under-valued in my humble opinion.
Don't have any info on the label I'm afraid.
I have just started including the odd card and cover in my collections, I like to show postal use of the stamps, it is what they were made for, after all! I have found some good cards myself when delving through dealer's stock, and have always found decent ones when I just "dip in" quickly, as opposed to standing there for half an hour or so checking each card. It is as if you get drawn to the card.