where i used to work my boss made a few stream traction engines, he spent around 10 years on each of them and they were the best machined bits of kit you have ever seen, tiny ball valve around 5mm big fully working you could turn the handle with your fingers, also he made a full set of mini tools around 15mm long, spanners, verniers, hacksaw and buckets they were were perfect, before the company went into liquidation he gave me the hand drawn drawings he did of them so if someone would like to look at them just say i can't post has they are worth alot and took him ages to draw and everything is to size, i will bring to a event to have alook