There are many examples throughout history and legend in Roundworld where a supreme craftsman has been killed or maimed by his patron or king so that he cannot duplicate his finest achievements for someone else. In Greek mythology example, the Greek inventor Daedalus was kept imprisoned by his patron, the king of Crete, so that nobody else could benefit from his genius; Daedalus escaped by building himself a set of wings and flying away. Another is the legend is that the eyes of clock maker Jan Růže (also called Hanuš) were put out after he finished the incredible Astrological Clock in Prague so that he could never build a clock that would rival it. There is also the Welsh mythological reference Llew Llaw Ereint (Llew of the Silver Hand) in the Mabinogion.
In literature there is a similar legend to the silverhand in the Dragonlance Chronicles of Margaret Weis and Tracy Hickman. The Silver Arm of Ergoth, created in history to forge the Dragonlances was passed on to Theros Ironfeld during the War of the Lance. He used the arm to construct the Dragonlances needed to combat the forces of evil which had risen again.
J K Rowling has also used the device: Voldemort gave Wormtail a silver hand at the end of Harry Potter and the Goblet of Fire.
Finally, Michael Moorcock's creation, the aspect of the Eternal Champion who is known as Corum of the Silver Hand: a cultured member of a dying race who, in a battle with human barbarians, loses a hand and an eye which are replaced respectively with a silver hand and a jewelled golden eye (formerly the property of a careless God...)
Finally there is a James Bond connection in both the movies "Golden Eye" and 'Goldfinger" and perhaps "the Man with the Golden Gun" (the latter likely a stretch although Pratchett has referred to Bond on numerous occasions in the past).
Dactylos itself is Greek for 'finger' so he is literally giving the reader 'the finger'.