Armchair Theatre
Something to Declare
4 October 1964, ABC
Role: Plinio

From the book, Armchair Theatre: The Lost Years:

This play -- a welcome debut -- was described by the caption writers as a "high class romantic comedy ... of the kind that cinema does so well ... and takes an American [William Marchant] to write the crackling sophisticated an laconic dialogue that such subjects need."

... Top of the bill for this production was Sylvia Sims, who had been a contract film star for Associated British Pictures for eight years, making her first appearance in Armchair Theatre. Co-star Jeremy Brett was no stranger to ABC Television drama, but he had just returned from the USA after filming My Fair Lady and being on Broadway. A very strong duo in the leads. 

Audiences liked it. The teleplay rated No. 5 for the week, drawing 7 million viewers.

IMDb page