Thanks in advance for any assistance you can offer. Just picked up this old tandem at a thrift store. It says Schwinn on the downtube (the rear downtube, not the front one behind the front wheel). The writing is barely visible, but is readable. It's 1 speed, coaster brake in the rear, rim brake in the front. It has the "generator" on the front wheel for powering a front and rear light (front doesn't look stock, but the rear one looks to match the fender perfectly).

Most of the components that are in decent enough shape also say Schwinn.

Note the middle "chainring" between the front and rear chainrings. It appears to be a chain tensioner, and I've never seen anything quite like it, especially at that size.

Needs some work, and I bought it for a fun project. Note the front stem is turned around 180 degrees. Many oddities with this bike.

Thanks for any input. Much appreciated!