I chucked out a (surface) rusty bathroom rad back in the days when Horsham council visited many villages on Saturdays in rotation to collect junk, green waste, metal, anything in fact.
As I threw out my rad I noticed a brand new one in the back of the scrap metal man. Gave him £5 for it. One of the seams looks badly crimped but I have filled it with water on my workhorse and cannot see any leaks. Might fit it one day.
On another occasion I visited an architectural scrap place, and in the yard was another rad, still shrink wrapped. Got it for £10 and when I arrived home and unwrapped it, it was in perfect nick so can only have been in his yard for a few days. Nice 1000*700 double with double fins and all the fittings. Made by Purmo.