RFTS Telemovie

And approximately fifteen years too old for the early 1940s part of the movie

Moggy

True, but if you shot it this year, he would only be 2 years older than Kenneth Moore was and I reckon he looks younger.
With the Harry Potter films finished what about Daniel Radcliff, Rupert Grint or Tom Felton, they’re all pretty good and would fit the age.