Last night saw a triple celebration taking place at Firehouse in central London - the official launch for the very desirable Scarfe On The Wall box set (a collaboration between Gerald Scarfe, Roger Waters, and luxury book publishers Gloria); Gerald receiving his CBE award from the Queen at Buckingham Palace on Tuesday, the day before; and the start of the charity auction for Gerald's wonderful, hand-painted, Wall design Fender Stratocaster signed by Roger, Nick Mason, David Gilmour, and, shortly before his very sad passing, Richard Wright.

The white, Mexican Strat is very possibly the final item signed by all four members of the "classic" line-up of Pink Floyd, and is up for auction with all proceeds going to Crisis, the homelessness charity.

Some iconic guitars have been auctioned this year, but this is truly special - iconic, signed, authenticated, bespoke and created in order to raise thousands of pounds for this very worthy cause. The auction is taking place online at www.BuyOnceGiveTwice.co.uk.

The finished guitar, signed and painted, went on-line yesterday and to mark this, was on display last night (and seen here in our exclusive pictures from the event; click the thumbnails to view the pictures in a larger format). It was attracting many admiring looks from those present, which included friends, family, and people involved with the box set publishers and the charity. You will need to register in order to bid on the guitar - if you are interested in doing so, and haven't already registered, just click here to visit their site and complete your details.

Whoever wins will not only receive an incredible, unique piece; but they will also be donating a large amount (it won't go cheaply) to Crisis. The winner will also receive one of the Scarfe on the Wall limited edition box sets.

If you aren't able to participate in the auction, you can buy one of the box sets separately, although you'll need to be quick – only 300 copies have been produced and a sizable chunk have already been sold. Scarfe on The Wall comprises eight stunning, high-quality, 16 inch x 20 inch prints (three of which are newly created pieces) signed by Gerald Scarfe (see pictures below) and an in-depth interview regarding the time when he created the illustrations for Pink Floyd's 1979 album The Wall and the accompanying film.

Roger Waters has signed the accompanying 'monograph' book which includes many early concept drawings for The Wall and a new interview with Gerald Scarfe. For more details and how to order, visit www.ScarfeOnTheWall.com.