Ten or fifteen years back, I had an ambition to buy such a vehicle and drive it around at Burning Man. I eventually settled for a deuce-and-a-half, which caused enough struggle and frustration that I'm glad I never actually bought a tank.
The conventional wisdom is that you need to buy several military vehicles in order to get and keep one up and running. Some things are going to come broken, some things will inevitably break, and the replacement parts aren't exactly at your local auto parts shop.
http://www.exarmyvehicles.com/offer/tracked-vehicles/tanks
https://mortarinvestments.eu/ArmouredVehicles
https://miltrade.com/pages/military-vehicles-for-sale-in-eur...
https://tanksales.co.uk/sales/
Ten or fifteen years back, I had an ambition to buy such a vehicle and drive it around at Burning Man. I eventually settled for a deuce-and-a-half, which caused enough struggle and frustration that I'm glad I never actually bought a tank.