oh, sorry

i own airplane parts ( coming from my father, who worked at the end of WW2 at Dornier in Friedrichshafen and Mengen as engineer testing the DO335 )

the part i want to know what it is and in which airplane it was built in
has a ID "JuN87689" and a brand or emblem ( a "W" in a circle, the "w" is overwritten with a "J" and a "F" )
my questions are
a) does JuN87689 mean, that this is a part form a JU87 ?
b) what sort of part is this ? What is is used for ?
c) does "JFM" mean Junkers Flugzeug und Motoren Werke ?
d) does anybody know this brand / emblem
thanks Fritz