The correct method of procuring a "burner" is to phone round the local auction houses to find out who has had a piano gathering dust for the last few months. Those with broken rest planks are a favourite as nobody would ever buy one because it will never be able to be tuned again. Auction houses are usually more than happy for you to come and collect these for nothing as they take up valuable floor space in their viewing room and nobody wants it to look like you can't shift stock.
In answer to the FOI request I can start them off with 2 from our grad night at Valley.
How is that purpose built piano burning with the natty 19(F) Sqn painted slabs area holding up these days guys?
