A1 4 is Clemens Wagner/ Braunschweig/Hamburg. They made lots of caps in the style as yours here. One find the VA stamp seldom. This is a nice piece. The Wagner caps of later make, i.e. 1938, were not the best in terms of quality and they fall apart. Yours is well preserved. A nice piece, to be sure. There is an extra stamp here on the reverse of the band which is interesting.