The Danza: A retroactive example. Chief Superintendant Strange is never given a first name on this series, but Endeavour gives him the first name of James, after the actor who played him in this series, James Grout.
Dawson Casting: There's a lot of it in "Last Seen Wearing" — in particular, then 23 year-old Elizabeth Hurley as a 16 year-old student.
Quite a few other famous British faces turn up as guest stars. It can lead to some rather odd experiences for the viewer, such as in the second episode when the prime suspects for a murder are Alfred Pennyworth, Richard Bucket and Trigger.