Bedford Square, London, as well as the surrounding area, still retains a wealth of Coade stone Keystones, Voussoirs and Blocks. In her book Mrs Coade's Stone, Alison Kelly (Upton-upon-Severn, 1990) illustrates various Keystones as well as Coade's original etchings for them. Orders for the Laughing Philosopher can be found in William Croggon's order book (Coade's manager) which are held in the Public Records Office. Two of these can be seen at the entrance to Bedford Square from Bayley Street.

An identical Coade stone keystone was sold here 22 May 1990, lot 62.