I think you are right opotable, this is a harp amp. In fact, Hohner still makes a 5 watt harp amp today. The 1946 must refer to a model number. I'm thinking that number is possibly a reference to Jacob Hohner who died in 1946.
I can't read the description, but the amp has definitely been refurbished with some modern parts. I can't put a date on it but stylistically it looks 1960's to me.
These little guys can be great recording amps although they are definitely one trick ponies. But some of them have a really good trick.