Help; Columbia Tandem Dual Steering, Year?

[Paulywood]

I've had this in the family since the 30's-40's, had Schwinn stores since 1918.

Can't seem to get the right pictures to find the year.
Front badge was removed when someone tried restoring it for my grandmother in the 80's.

Under Frame on rear crank set reads 3877.

thanks for info, I hope.
Paul

 

[bricycle]

Pretty darn cool!