Its not a bomb sight afterall,check it out

[Daveroo]

my great grandfather had it in his workshop for as long as my dad can remember,we have no idea of how he came to have it.
its a Sperry Gyroscope,K-13,Compensatiing Sight,the part number is 659060
i looked online and found some info,seems they were used on the M2 .50cal waist guns on B17,B24,B26 and maybe other aircraft..i dont know,it seems to be fairly complete,as the two i saw online were both missing the round "lens",this one has it in tact.

[robert41]

That is a great piece of history you have Dave. Take good care of it. Perhaps, one day, you would consider parting with it, to a museum or a restored flying bomber.