Saw a 504 wagon going the opposite way and my lady said it had a for sale sign at the same moment i noticed it was a diesel. Did a u turn as quickly as possible [ big tickets for u-turns in Montreal] and tried to give chase but lost him after a couple of lights. Hopefully will find him again as i live in the Rosemount area of Montreal where it's mostly French and where you can see Citroyen CV2's and DS's almost everyday. I would love one of those as they probably hold more than my Vanagon and tough enough to win more than a few african rallies in their day.
They were still making them brand new in a few African countries, up until just a couple of years ago.
Archive.org shows the 504 wagon last sold new for between $19 - $20K USD in Nigeria, back in 2005.
Very tough cars, still lots on the road in Africa.
If you really wanted one, you'd be better off finding one from somewhere else. Montreal road salt absolutely kills cars with rust.