I know Ian's brother in law or cousin worked / works for cosworth , years ago he couldn't get them made as a single set it was always large batch orders so maybe they have changed the policy and are happy to machine a set of Pistons . I can remember him telling me he paid a few grand for a lorry load of wrc focus zetec engine parts , he had around 20 cgi blocks and was selling them for a £100 each lol