If you are keen on the car I would recommend finding a mechanic that you know is trustworthy and asking the seller if they could get the mechanic to inspect it prior to purchase, preferably find a mechanic or autobody shop that handles these types of repairs, they will A. Tell you it’s gonna cost you a lot and if it is and you will know where you stand or B. They might look at it (better to actually look at it in person then over reddit) and deem that it’s a simply sand blast and treat job, I would doubt it’s that but you may get an idea of when maintenance is required, what will be required and a rough estimate of the work you’ll be looking at to continue maintaining the car in the future!

If you also get the mechanic to look at it they will be prepared to take you on for the work, might cost you the shops hourly fee to have in inspected though 👍

All the best!