The Trek T50, T100 and T200 have the same frame. In period test reports, they were noted for having long stoker cockpits.

We have a T50, and love it. Here are three listed on SF Bay Area CL:
trek t 100 double cross two person bike
two person bike
TREK T-200 TENDEM BIKE

The IBIS tandems of the late 1980s/early 1990s have a very long stoker cockpit; longer than out Trek, and have ISO559 (26") wheels.