So, one of the Imperial Club mailing list guys, Allen M., connected me with Michael A. in San Jose, CA, who has an intact Imp MD car. I plan to visit him and his ride next week.
In other fix-up news... The steering box is rebuilt and installed -- works fine, drives straight without any slop. The open seam on the rear seat has been restitched -- looks perfect. Getting a set of new tires mounted tomorrow. Wheel alignment, ball joints lubed, etc. Wheel bearing repack? Maybe. I bought an original shop manual, which should help with lots of tasks. Will visit the hardware store tomorrow to see what size pipe will thread onto the table mounting point.