If the price is right (ie, as close to free as possible...) and you've got the space for it, I would absolutely get it. The perfect tandem? Almost certainly not, but it's cool looking, it's French... I would not be able to resist! OK, the one thing that might cause me to resist is if the wheels are 27" and the cantis don't have enough travel to accommodate 700c.
Thus far I've only been able to get my stoker to go on short rides to the coffee shop or the local farm brewery, but I really enjoyed 'renovating' it and I'm hoping for some longer rides in the future.