1920's Gretsch mandolin / banjo - $600

920's mandolin banjo - made by Gretch or William Lange out of New York -the only part that isn't original is the skin and the tail piece -which the original is in the case.
Really nice piece -I've owned it for about 30 yrs.
and never played it.
I did have the new skin put on that long ago.
Asking $600