This is listed as 59.5 front, 59 rear.

Used Freschi Lugged Tandem Bicycle Frameset Excentric Campagnolo Headset | eBay

It would be a little on the tall side for the Captain, but it should work.

And, it should be fine for the stoker.

Perhaps try a 60cm regular bike, and see how it feels.

If you live in a city named "Milan", you NEED TO RIDE AN ITALIAN BIKE!!!!

It doesn't look like it'll be ready for a test ride, but perhaps the seller would entertain an offer if you could make it to Chicago.