The auction will be run by Spink and proceeds go to Kids Company and the British Association for Adoption and Fostering.
The low serial number £50 notes honour the pair for their steam engine but Boulton also minted high quality coins. For the true specialist, you can also place a bid for some of the first printed banknotes signed by Chris Salmon, as issued last week.
Auction starts 5.30pm. Online bids accepted. Full details at www.spink.com or call 020 7563 4000
NOT content with designing the stunning Olympic cauldron and the new Routemaster bus, Thomas Heatherwick has teamed up with Transport for London to produce a limited edition Oyster card holder for the London Design Festival. On sale from today, the cork design uses the flooring material of the new bus. And if you aren't lucky enough to take a Heatherwick bus into work, you could try persuading your office to adopt some of the matching furniture due to be unveiled this Wednesday.
Oyster holders are £25, from www.tfl.gov.uk/shop