If it can be found, the author that went under the name of LBSC[r] produced a marvellous book on live steam, specifically about his design known as ''Titch''.
this is/was an 0-4-0 tank live steam, passenger hauling...but despite that, the author covered all concievable aspects of locomotive construction..I learnt all I know about Walschearts valve gear and how it works, from his description.